I wouldn’t say that. I mean, optics is one thing and if the natural skin, hair, and eye colors are good enough for you to pretend being a High Elf and roleplaying as that, then great! And if not, then too bad.
But the design isn’t broken because of the addition of those customization options. I mean, the story background does offer Blizzard some creative space where they can add customization, because the premise isn’t that all Void Elves are affected equally much by The Void. That’s why we can customize the degree to which we want our Void Elf to be affected by The Void. Now there are just more options that allow you to be less affected.
The only premise there is for the Void Elves, is that they are affected to some degree. The customization is allowing you to choose how much.