The San Diego Comic-Con 2019 had Marvel Studios giving us a full slate for Phase 4 but had announced nothing concrete of the Marvel Fox characters like the X-Men and the Fantastic Four. For anyone still worrying about whether the MCU already has control, Disney CEO Bob Iger has confirmed that the characters are all now under the Marvel Studios banner under the control of Kevin Feige.
Iger had announced it during Disney's shareholders' meeting (via MCU Cosmic):
During Feige closing lines at the SDCC 2019 panel, he did say that there was "no time" to discuss Fantastic Four and "Mutants". Just by mentioning FF first, I have a feeling that Marvel Studios is prioritizing the return of Marvel's First Family. After all, Fox did botch it with the infamously terrible Fant4stic that came out back in 2015.
We don't know how Marvel Studios plans to introduce any of these new characters, but there has been a lot of hints here and there. Spider-Man: Far From Home has revealed that the former Avengers Tower has been renovated, and it looks to be the new Baxter Building—at least, from what fans can guess. Some are also suspecting that Scarlet Witch will have something to do with the "birth" of Mutants come Doctor Strange in the Multiverse of Madness. It's just a guess, but it does kind of make sense that she would create them as a mirror of what she did in House of M where she made mutants disappear.
For now, fans are hoping for some big update come the D23 Expo this Aug. 23–26.
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