The Betrayed can't recover. They've gone through evolution to become what they are now, they aren't simply just blind snow elves anymore. Hopefully Gelebor can teach them to be peaceful.
If this is indeed a case of evolution, a 'recovery' can not be impossible. Evolution is a process that never stops and something that changed once, can always change again. If the betrayed were to start living peacefully, and more like the Snow Elves used to live, then their physical appearance would likely change again over the next couple thousand years. Not necessarily to what it was before their corruption, but if it was possible for them to evolve into something more primal, they can also evolve into a more sophisticated race again. Evolution allows you to adapt, so if their living conditions change, they do too (slowly).
In any case, I wasn't really talking about a physical recovery. The problem is what they do, not what they look like imo.
