Honestly, if they were wiped out it’d not be a surprise at all. The only thing we need to be 100% sure Blizzard hates the Night Elves is them saying it in a Blizzcon.
But right now I am 99% sure they do.
Aside from that, could also be they never encountered Kalimdor. Otherwise, the Human/Orc centrism in this story is something I am surprised the devs continue to push forward.