Not all "high elfers" consider "High Elves the main elf group in WoW", I've always said that kind of dumb, the kind of talk disputing "the true high elves". It happens on both sides.
But about the main high elf group being Blood Elves, sure whatever. I think you'll find that vast majority of High Elf fans like that High Elves are this downtrodden group that managed to uphold their ideals even at the cost of their lands/family. Their loyalty and friendship with the Alliance is something a lot like. That they're seen as traitors to Blood Elves doesn't have any bearing. So this point of acknowledgement is pretty weird.
People for instance don't care that Vulpera are a ragtag group of foxes that have no kingdom and are basically scavengers. Not everyone in the game wants to play an elf in a "majestic and magical city". Since there's two of those types of Elves on Horde (Nightborne and Blood Elves), it's not unreasonable for there to be two of another type, "woodsy", for Alliance.
Woodland theme works perfectly well for High Elves, just because there's a ton of them in Dalaran isn't be all end all of their theme. Regardless of being in Dalaran they are often depicted more times as Rangers, there's lodges out among Alliance lands that High Elves created.
Just because Dalaran exists doesn't mean Blizzard can't create a new location for them. Look at Void Elves, Blizzard created a "Rift" in the middle of fuck nowhere to give Void Elves a place. Void Elves who are former Blood Elves didn't have to have a "magical and majestic city" just because Blood Elves have one.
These arguments you're using fall apart when you apply them to the other AR, which means it's not a good argument if it has to be that specific.
And you're harping on numbers when Void Elves themselves didn't exist until they were made an AR. Even then were described as a "squad". There's already an imgur album going around of 100s of High Elf NPCs in game, which btw isn't to say you take in-game numbers as literal because Stormwind isn't just a city with 200 some NPCs and neither is Goldshire just an Inn and Blacksmith Forge.
But it's meant to point out there's less Void Elves than High Elves and Void Elves were still able to become an Allied Race.
Again, if you're using arguments that don't even work on Void Elves, when they actually exist, then Void Elves shouldn't have become an Allied Race either. What does that say? That means Blizzard ultimately didn't give a crap. Exactly as they said, Void Elves came about because they wanted "to do something new and cool".
So all this discussion is showing Blizzard, "hey you can also do something 'new' and cool with the High Elves on the Alliance" with all these customization and model suggestions.