I think Brock's just being Brock. I don't think he views UFC as more than a leverage play for his negotiations with Vince, and Dana probably doesn't mind helping him in that. UFC certainly needs him back if he actually wants to go, as most of their shows are basically WWE Battleground levels of mediocre/bad at this point. They're in the same boat as WWE of having to produce too much content with not enough stars. Nothing feels important aside from the main event, and maybe the co-main, and everybody is the same GH'ed up guy with tatoos and an unfortunate haircut - and that's the opinion of someone who watches the shows every month.