Disney recently purchased the Fox Studios assets, which includes the X-Men, Deadpool, Wolverine, Fantastic Four and all the related characters that come with it, with the deal currently being finalized and will go through by the Spring of 2019.
THR questions Bob Iger if Marvel is going to absorb Fox’s X-Men franchise, and is Kevin Feige going to oversee everything? Iger responds:
I think it only makes sense. I want to be careful here because of what's been communicated to the Fox folks, but I think they know. It only makes sense for Marvel to be supervised by one entity. There shouldn't be two Marvels.
Iger was also questioned about Deadpool joining the Avengers:
Kevin's got a lot of ideas. I'm not suggesting that's one of them. But who knows?
Regarding Iger mentioning "two Marvels," I think he meant the X-Men potentially being overseen by Disney separately, and not by Marvel Studios, but we see that is not the case.
Iger's words are also interesting because we know Marvel Studios (the MCU movies) and Marvel TV (SHIELD, Netflix series) are separate at Disney, but Iger seems to be stating that Marvel Studios gets first dibs on the X-Men.
Basically it sounds as if Kevin Feige has the final say on what happens with the X-Men (and probably all of the Marvel characters) in the movies and on TV.
For instance, if Feige and the MCU movies have really no interest in so-and-so characters, Marvel TV could use them for whatever they want.
Iger also previously said that they have plans for the Marvel Fox characters as being a part of their new upcoming Disney Play streaming App.
Recently saw it reported that Feige and Marvel Studios are developing numerous series, including Loki and Scarlet Witch, for Disney Play, so as I put it forth, it's possible Feige may also be using the X-Men and Fantastic Four characters for their new TV series for the app.