What about protodrakes? Blizzard says they didn't exist on Azeroth pre-Titans. So then where did they come from for the Titans to make them into dragons? Some of these species came about during/after the terraforming.
The Aqir built their empire on Kalimdor (which didn't exist until after the Titan terraforming). This was several thousand years before they were defeated by the Trolls 16,000 years ago.
As proof that Blizzard doesn't think this shit through. One source in game says the Qiraji came from the Aqir (whom were created by the Old Gods). Another source in game says the Qiraji came from Silithid (whom were created by the Well of Eternity and modified by C'thun).
Trying to make sense of this is putting more effort into it than Blizzard did when they wrote the lore or made those comments.