I'm not a fan of Nobbel but at least he tried to push on a few of those lore questions in his interview before he realized 'oh god, Blizzard will probably not let me interview them again if they don't like me calling bullshit on their answers'
Though it seems clear Blizz just straight up doesn't have an answer for where this first Gen of Centaur in Dragon Isles actually came from beyond just... sprouting up in ancient kalimdor. How did the first gen of centaur come to be if Theradras and Zaetar didn't make them?
It's really very frustrating, even years after quitting the game, that they still don't care about the quality of the narrative in such a basic way.
EDIT: Corrected a sentence in the second paragraph.