Exactly, a lot of what you've said simply works out by itself. And it's fairly obvious to see that happening in the community right now, where it's mostly fans of Blood Elves who show a level of animosity unlike any other towards the request. And on the flip side a lot of the most ardent defenders of the request happen to be Alliance fans.
Seems like a cop out then to say 'no no we have more faction integrity by not allowing two fictional groups who tend to butt heads/kill each other by only allowing players to play one side of it!"
Again, I think because it was looks that were prioritized and probably stemming from because fans of Blood Elves simply want customizations that have been suggested here, for themselves. Not unlike Night Elf fans requesting for Highborne looks and having some come in to say Nightborne are the Highborne (how ironic is that?). That's why I want to see what occurs after Blood Elves get their extra customizations.
As the High Elf request will continue to happen after increased customizations, it will destroy the "you just want the look" argument because if that's all the requesters wanted then the majority would move over to play Blood Elves and the request would die out.
Won't happen though, just like how there's been Blood Elves in the game for years and those requesting High Elves haven't just all moved over to playing Blood Elves when they finally were included in the game.
This request would not be a thing if Blood Elves were ever the answer to the High Elf request.
It's kind of like the other requests for the game: the unpruning, the less rng, the return of tier sets because of their looks not necessarily set bonuses, getting pvp vendors back where you can purchase pvp gear.
All major requests have very specific asks and don't go away with the majority until it's been granted to a strikingly satisfying degree.
And no Void Elves are clearly not the "strikingly satisfying degree" seeing as they're twice-removed from High Elven Exiles, are ex-Blood Elves, and go against the very background of why High Elves separated from their Blood Elven brethren in the first place: going all-in on use of chaotic magics.