They added him to the lore and it just works. Plus, because they are all dead means nothing, check our bonny friends, this guy shoud not even be here but still, he's here. Why can't we play orcs and imp ? Would be so much fun to play all species of Rivellon.
I mean, in D: OS 1 and every other game so far from Larian I played you only play humans, excepted for the D: OS 2, and it's great ! I can probably found the answer on internet (lore) but my real question is: why they (Larian) did remove them in the lore ? Technical point of view, I don't get it.