Agree to disagree, there are lore compliant explanations for fair skinned Void Elves as well as if/when normal hair options come into the picture.
Blizzard didn’t just put those High Elves in the starter hub for fun, they deliberately designed it to show that High Elves are joining. All customization options are canon, or else they wouldn’t have been added in the first place. It’s safe to assume that when you play as a fair skinned, and/or eventually a normal haired, Void Elf you are playing as a new member.
If that wasn’t the case, there would be Void Elves being manifested from nothing. I can’t find the source, but it’s supposedly been said that the Void Elves are a small and elite force (something like that, feel free to correct me on the specifics of the line). If they were never creating more then it wouldn’t make sense for players to make more and more. It’s the entire reason, as I said, for why Blizzard actively shows NPCs entering the hub to join.
Also, as for the claim that they’re not recruiting. This isn’t entirely correct.
"They’re not … recruiting , necessarily, but they’re open to those who show a similar interest.”
That is the direct quote. Not only is “necessarily” used, but it also essentially is saying that they’re welcoming others in which is exactly what’s shown in game. Additionally, recruiting can also mean actively seeking out new members which doesn’t apply if new members are coming on their own.
Lastly, they don’t need to change any High Elf NPCs or Alleria.
Also another quote:
“What is the process for choosing what sort of customization options each race gets? We’ve seen a steady stream of updates for each race, with some updated over several months such as Orcs getting their fist round in April and then another round today in July. Are some races revisited to add more options pending community feedback?”
"We try to make choices for race customization that are appropriate for their race, ie Night Elf hairstyles and ornamentation core to their fantasy. "
Also another quote that shows Blizzard is open to expanding more normal options to Void Elves:
“We did have a lot of discussion about it, ultimately we might do more in the future, but for now we’re providing the option to have a few High Elf customizations available.”