Personally, I’d love the night elf facial piercings to be expanded to other races so the other elfies can also get nose rings and studs.
And more extravagant hair colors, since azeroth has dyes I don’t see why the majority of races (besides races like taurens and worgens) can’t have more colors of hair besides natural.
Green skin trolls.
Like, I’d legit play troll on my priest if they implemented that now that cross faction is coming, it’s currently a nelf.
I assume more character customization will arrive with the next expansion, so my expectations are extremely high. I think other games offer far better character customization than WoW, and I don’t think Blizzard can get away with drip-feeding its playerbase a handful new haircuts every 6-9 months anymore. The dissapointment if they do will be tangible.
I think spell and ability customization is something that is severely lacking and something that needs to happen on a large scale.
Shamans have it where each race has its own unique totem design.
Warlocks and Death Knights have various glyphs that allow them to customize their summonings.
Druids can customize their shapeshifts.
Other classes have bits and bobs that they can customize through glyphs.
But it all amounts to minor additions in the grand scheme of things and it’s just not enough.
I expect Blizzard to increase the customization in this area by a factor of 10. Less than that and the dissapointment sets in.
I expect every race to get the same amount of customization that for example Humans and Orcs and Night Elves have - if not more. Even those races feel a bit on the low side in 2022.
Then there’s a lot of bonus stuff, like Blizzard could offer differnt voices for the various races. There’s something to be said for more sub-race customization options or downright new Allied races being added.
And there’s something to be said for delivering on various player requests over the years, like casting animations utilizing your weapon or adding special jump animations for non-elves, or whatever.
But that’s mostly bonus stuff.
Spell and ability customization and basic race customization is what I expect. In a large quantity. Volume is what matters. That’s what I expect from Blizzard. A horn of plenty. Because I get that in other games I play, so I feel like I should also be able to get it in WoW after 17 years.
Kul Tiran:
Sorry, what exactly that is cross faction is coming? 
The females being a bit more feminine is all I need. Obviously whoever needs to get off there are good websites for that – but I’m sick of looking at my human females behinds and seeing something I can only imagine is the result of an extensive hip reconstruction surgery.
Or let’s call it like it is: they have no booty.
Americans and their pretentious prudence, meh. Having a female have A VERY CLEARLY shown hip to waist ratio is not going to get them sued, I’m pretty sure. Or having their booty actually look like, you know, a booty.
Only the Draenei girls have a very obvious female body outline, sadly. Everything else can easily be mistaken for a man if you lower your brightness just a little.
why cant tauren/worgen have different coloured hair?! we can dye them just like everyone else.
more varied hair colours for tauren and more and different flowers for our hair. thats pretty much all i want. maybe let us choose our hair colour independently to our skin colour as well.
edit: oh yeah, also, give us battle scars
Thank you, I had no clue. So it’s finally happening. Would love to see a future opt-in for LFD as well.
I wish void elves got some more void themed customisations, be it tattoos, scars or hairstyles, or just about anything related.
For us blood elves, to get some of the hairstyle/color options from velves and again, expanding the roster of thematic customisations would be neat (warpaint, tattoos, red eyes for the sake of dark rangers)
In the case of both races’ females to be able to change their nail polish color 
as well as their makeup of choice.
But, there are other races direly in need of some love so I can suppose I can wait a little 
not every player is an elf after all.
Moar ponytails, especially for those poor souls that still can’t have one in 2022, unplayable
Aside from more scars, I’d love to see 3D eyebrows for normal draenei that are the same colour as the hair. 
Scourge facial tattoos for Death Knights.
I want customization of the abilities.
I mainly look forward to more appearance options like height, weight, voice etc. Feels more like a personal character with these options. I know… kinda like FFX, but its okay to steal the cool things right?
For Blood Elf:
Dwarf:
Worgen customization
• New mustaches
• Another new beards,also customizing
Both of them
• 3 different types of Tails
• Few new skin colors
Zandalari and darkspear males getting new beards and another tattoos
Death knight new unique customization
• Runic Tattoos (Blue but Copy of the DH types like "Betrayer")
• Kul Tirans getting DK skin colors from the Humans/dwarves/gnomes and high elves,idk if nightborne gets possible about night elf dk skin colorsVoid-themed customizations for Void elves, and Dark Ranger customizations for Blood elves. Tattoos and scars for both. Also more customization for Kul’Tirans and Zandalari Trolls.
Long beards, tattoos, scars for Humans and Kul Tirans. More tattoos and scars for Dwarves and Dark Iron.