While I agree that velves are a giant ass pull (bigger than tauren paladins or WoD time travel) that makes no sense, you cant forget that in WoW story was always just a background for gameplay, not the other way around.
Blizzard has twisted their lore in the most bizzare ways to crate space for what they think makes good gameplay so many times already that Im suprised someone who plays for the story is still around.