Fair enough, but aren't there races from Azeroth or Draenor that fill those other tropes? For vampires we have San'layn, for fauns we have satyr, and for giants we have vrykul and ogres. I'll give you angels though, there's nothing quite like them I can think of.
Selfishly, I'm just not very fond of the idea of people from the afterlives coming to fight for the Alliance and Horde, but I'd get over it if they did end up playable.