It’d be pretty stupid if a Pandaren who wasn’t actually found or be properly in the lore, to be a deathknight. 

That’s like letting Alliance riding  Deathwing and the forsaken resurrecting Arthas to make him the new leader for the forsaken. 

That first one is a thing that I’ve done. Mind you, he wasn’t happy about it, and he did try to barrel roll me off but the point is have this cool lorebreaking picture: