I have a feeling this will be long comment, I apologize in advance.
I don´t see how existence of settlements determines potential for interesting roleplay. In terms of lore, Quel´Danil Lodge has just as much lore as Tranquillien or Fairbreeze or any other minor settlement.
You are correct about capitals, but I think the same could be said about Darkspear trolls, who technically have a capital city, but it doesn´t really have anything going for it. Yet it doesn´t make Darkspear inferior to Zandalari.
Alright, who am I kidding, they are inferior, you´ve got a point there.
I think this could be said for many other races. I don´t think there is some drive for tauren, Darkspear trolls or even ordinary draenei since Legion was defeated. Dwarves also lost much of their drive with conflicts between clans ending and many secrets of the Titans being discovered, yet I wouldn´t say they don´t have potential because of that.
Roleplay is often about creating your own stories that are set in the setting, which is good since progress in the main story relies entirely on Blizzard and I doubt they will ever give gnomes or worgen their homeland back, or allow night elves to take revenge for theirs.
I refuse to acknowledge Wet Fart Covenant and Gingerbanger as THE high elf faction and racial leader. Kill them all.
I understand why people might see problem with high elven roleplay. I don´t think we should see blood elves as default and high elves as some copycats when it comes to story, because they both have equal right for Thalassian heritage.
But when it comes to roleplay, situation is different and I wholeheartedly agree that doing things like Farstriders, Magisters, paladins, Silver Crapenant or any other concept that can (and has been) done by blood elves, is pointless. It would just end up being an inferior version of blood elves.
City elves in Stormwind or Dalaran are just other side of the same coin, if you want to be neutral researcher in Dalaran, you might as well be a blood elf and I have yet to see high elf in Stormwind that offers anything human or void elf wouldn´t.
The reason why I mention Quel´Danil elves in pretty much every comment here is because I believe they are the only group of high elves that are really unique, not only among Highborne elves, but all races, for reasons I mentioned above. I think having elves who purposefuly avoid magic might lead to interesting conflict RP with their allies, who all seem to be fine with Arcane.
I know that feeling, happens all the time to me.
I don´t think there´s anything wrong with people commenting about problems high elves as a concept might have. It might even clarify potential issues high elf community should deal with and how to make it better.