With all this squabbling between Marvel and Fox over the X-Men (and FF) movie rights causing all sorts of trouble...
Disney has deep pockets, why don't they just make Fox an offer they can't refuse? Everyone has their price.
That would seem to handily solve the problems. The X-Men (and FF) can get the in-MCU treatment they deserve. And then other related franchises such as Gazillion can then treat X-Men like Avengers.
There must be some deal that would be worth it to Fox, either for Disney to outright buy back the rights, or they go for a revenue sharing deal like Marvel has with Sony to get Spider-Man back where he belongs.
EDIT: I can see that Marvel wouldn't have had enough money by themselves to get the rights back, but after Disney bought them its a whole different situation.