I’d say that this is the result of just doing nothing with the flights since Cataclysm. The most active dragon since was freaking Wrathion, and beyond that everyone else has been sitting around doing nothing. We should have seen at least some indication of the other flights doing things post-Cata. Hell, I still think the Bronze Dragonflight should have played some sort of role in WoD.
Granted, I don’t like the motivation of the flights in this expansion. Getting back aspectral powers should not be a thing, because they gave up that power in Cataclysm. What should be their motivation is to carve a place/purpose for themselves in this world. That would make a lot more sense without the need of titan power-ups. This gives the flights something to truly challenge them while making them vulnerable. It would also help keep the incarnates as a threat to everyone without needing to make them something too powerful (in other words, keep their power level grounded instead of having to be yet another old god-tier level threat).