I think they cant hadle too many races in the game, or ok they would, but its hard work, you have to create armor models and such things for every different race. Anyways, if they implement all of them i think they will little by little, one each expansion or something like that.
cant be hard to make armor for alot of races just because it common practice to have 1 male & 1 female body they just resize and then they only need to make 2 set of armor, just like the bones theres only 1 set of them. they might add litte differences and build a place for a tail but im pertty sure they have a mock up template for everything.