My strongest instinct tells me if blizzard were going to work on a capital for night elves, it would be Hyjal - Well of Eternity and Nordrassil are the arcane-nature duality power central to the race and they are both there.
If they don’t build one it’s going to be Suramar whether they share with Nightborne or kick them out - it’s the most practical choice and far easier to change lore than design yet another capital.
Eldre’thalas is a 3rd choice option, but it’s old design and at this point using it you might as well rebuild it from scratch and if you are building from scratch Hyjal makes a better local, more sense and is a nice location. But Dire Maul is a viable option, either as primary capital or 2nd NElf city after the one in Hyjal
My future Prediction of Night Elves with Hyjal Capital
The night elves are alliance only in name, they help EK group with nothing, and don’t ask for any help - they are focused on rebuilding (Highborne focus on civilization and progress, Druids on restoring nature and balance/harmony, Priests still govern making sure everything holds together and the NElves don’t go off course. However they all watch global affairs closely, making sure they are never caught off guard and are prepared.
I also predict Shadowlands will restore the WoT slaughtered Night Elves and it would be very welcome if the Farondis also get that miracle too
A better, brighter and bigger Future For Night Elves
Night elves, are now crazy about regrowth (druids) and Development (Highborne led) - they harness their power fully, to protect their lands from ever being at the mercy of other races and to make sure they’re race and civilization recover into a power house. It is not a drive for an empire, but rather that the places they call home will be restored and secure.
Amongst the night elves, the druids seek to regrow all the forests lost and heal lands, the Highborne lead efforts focused on restoring the ruins and as much of kaldorei civilization as possible. Highborne do not have the respect they took for granted in the pre-sundering era, so they are very focused on trying to prove they are the high calling they were once believed as. They engage with the rest of the world, and are known for having high standards almost as if “we’ll teach you how to live the right way” They do this from their centre in Eldre’thalas - they rule western and northern Feralas spilling into much of desolace, but unlike Hyjal, they’re far more engaged with the world, trade etc, and serve as the defacto night elf civilization on Kalimdor - while Hyjal is full of researchers, and is more considered a sacred capital - the Highborne study and utilise the Well, the druids the nature and the emerald dream through the tree, and a new Cathedral to Elune and primary HQ of the Order of Elune is built there. The Cathedral of Eternal night is the broken isle chapter, Nightborne and Val’Sharah priests that moved south operate it there - Elunites do pilgrimage to Hyjal, though it is mostly night elven. However CoEN has Nightborne, Fangfire worgen, Void elf races involved.
This effectively makes the NElves two major operations, but the greater focus is on the Hyjal faction. This is what the game will focus on when dealing g with night elves mainly, Highborne will be background
Highborne Alternative
A recent proposal caught my eye - Blizzard swing the Highborne over to Suramar that opens itself up as a neutral sanctuary city due to political developments.
In this scenario, the Nightborne are still horde but the city is open to Night elves too, and alliance Highborne migrate their - together they start a kaldorei civilization rebuild initiative - most Highborne development continues via the broken isles alongside the Nightborne, think of it as a Dalaran, but horde centric instead.
Blizzard here choose to develop future Highborne stuff in conjunction with the Nightborne, leaving Kalimdor more right elf wc3 group , heavier priest/druid focus and minute highborne presence.
How the Various Night Elven Races/Groups look in 10.0
A new night elf grand Holy capital is on Mount Hyjal. It’s the best location if you’re going to build fully for the night elvs - but if you’re not, it’s the broken isles. Hyjal has the Well of Eternity, the Tree, the wild gods. Build a great city, and a temple, and there is lots of forest for miles around - it can serve as the central hub for the kaldorei moving forward.
•Highborne will have their all capital in Eldre’thalas [Alliance] Or shifted to Suramar
•Nightborne in Suramar [Horde]
•Nazdorei (future allied race based on naga/night elf) in New Zin’Azshari - Nazjatar [TBD - but likely alliance, could be both]
•Fangfire Worgen (new Worgen NElf allied race) - Shal’anir Val’Sharah [Alliance]
•Darnassian Capital - Hyjal
Hyjal capital would actually involve druid culture too amongst priest and Highborne. Yes Highborne will have a huge presence due to the well, druids because of the wild gods and trees, and Priests will have a temple built. And no, no tree city, Nordrassil and the surrounding forest is the tree portion, architecture is pre-sundering but full of nature and life as all aspects meet.
The capital on Hyjal, New Elundis, is not your typical city, sure, trade happens etc, but access is mostly through portal and with permission. There are very strict rules of behaviour and contect, and many no-go areas for visitors. The well of Eternity sacred to the night elves is there and is the frontier of arcane research and development, while the nature wild gods so revered by the night elven druids also reside there as a land deeply connected with nature. the restord forests are huge wild lands, but you can often see wild gods visiting the city, and the massive tree in the centre hosts many unique life forms as a gateway between the dream and the present.
Deep Dive
they’ve probably gone a lot further in the healing/cleansing of the forest arena, the Druids have learnt to tap the power of the Emerald dream into the world in ways unknown previously (this follow Malfurion’s gains in Stormrage book), the night elves are now using their powers fully - both well of Eternity and the Emerald dream world tree.
They are very determined to be strong enough to defend their lands (priest), guard nature (druids) and be the leaders of civilization and progress i.e. show the world how it’s done (Highborne).
They consider themselves the only ones truly responsible enough with this power - having witnessed the other races often abuse power, and realising they (after Azshara’s reign) have really proved themselves not only capable but the best at managing and the best equipped to do so. They highlight their society as being the most balanced and capable of dealing with and utilising power effectively.
it’s not all talk. While they remain mostly reclusive and autonomous to the rest of the races, they work with wild gods, the blue flight (highborne) and greenflight too. The druids (incl tauren, trolls, worgen ones) are very much involved in Hyjal though it’s the night elf capital. they tap the power of the dream to heal the forests. The cenarion circle isn’t dissolved because the Night elves made their capital in Hyjal, it continues its work on and in the great tree and surrounding forests, druids intermingle with the night elves in their city, though they mostly stay out in the woods.
It’s not the the priesthood don’t trust the Highborne, they consider it their duty that Kaldorei civilization would never go off kilter again, so they watch and monitor - but the way they do this mainly is buy maintaining the moral rectitude, and discipline of the people, the thing is , the highborne badly want their reputation and revere restored. Farondis restoration boosted this a long way, but the pride of the Highborne is what forces them to be even more diligent, they don’t want the people to ever think they’d repeat the past and that they can be fully trusted, they are also driven by proving to the people the Night elves do things best, and they are most capable.
As such they quickly ascend to handle progress, development, diplomacy affairs, and while the priests deal with internal affairs and leadership buck stops with the High Priestess, the highborne are the international face of the Night elves handling most of the interactions with other races, although a priest usually accompanies (not because of trust issues, but their position of leadership).
Although they operate in very different locations and spheres. Prince Farondis, Tyrande Whisperwind and Malfurion Stormrage are the 3 main leaders the Kaldorei honour the most and look to and are the 3 most trusted. Farondis has respect from everyone, and is the main reason the Highborne are trusted by everyone a lot more than previously His contribution is obvious - as Tyrande isn’t actually that concerned about night elf progress and development - but more spirituality and military defense, while Malfurion is still far more concerned about nature, and the harmony of the race.
Highborne In Broken Isles Alternative
In the Highborne mostly go to Suramar alternative - Prince Farondis is instead involved with Suramar and broken isle affairs, considered alliance friendly because he is night elven, he is actually neutral. New night elf isolationist leanings make for stronger broken isle ties, but they are still separate. Broken isle people engage more with others and it is those islander night elves that are friendly with Highmoutnain (they’ve been living close to and peacefully for 10k years - it’s not going to change cos HM went horde) and Nightborne their kin in their mutual city now opened up they helped wrest from the Legion doing a lot more than Tyrande’s group - Nightborne have no reason to reject or alienate these night elves even if they’re on the horde and these ones are not : Suramar and the Nightborne while in the horde are not super horde loyalists that ignore everyone else - that’s why it considers its city neutral for elves even though it’s leadership aligned with horde
But blizzard here tie Highborne and Nightborne together and use the isle to develop a more civilization focused night elf/Nightborne world.
If they want to take it a step further, they could make NElf highborne like the Illidari, a neutral group that you can role play as a night elf mage, you helping the kaldorei/shal’dorei efforts as your main focus rather than the Hyjal efforts. You can choose to ide tidy with both just like DH and DK Nelf characters can as their faction is not loyal to the Darnassians.
This allows player Highborne lovers to sort of have what they’ve always wanted i.e. kaldorei civilization proper without feeling like they’re being traitor or joining the horde. Their initiative with the Nightborne becomes focused on developing the fallen Elven night civilization. It also allows some complexity and nuance to elven affairs which is acceptable imo.