I wonder if it was more of a tone issue, maybe he wanted to go straight comedy with it? I’ve been curious about the same thing. Wright has a bit more mainstream cache, though, maybe Gunn knew he needed to “go along to get along” to get this made and get higher profile gigs? Just spitballin’.
I have actually been rereading the “Annihilation” series since last week, and the whole Nova story arc has got me thinking about it a lot. I really do think it would be cool to somehow incorporate the Nova Corps and what happens with Richard Rider into it, but I just can’t see them going that route anytime soon. Maybe in a GOTG sequel. They have no clue how the “Cosmic” stuff will translate in terms of money yet. Would be a really big risk to commit to Nova without knowing how this one does first.