A hidden society of mutants are revealed to the world.
Experiments.
Snapping into existence in the Infinity Gauntlet.
Recent spontaneous evolution. (a few in the beginning, and more come with time).
Other
In the Avengers 4 end of credit scene.
A mysterious man walks up to the Avengers, can’t see his face.
Tony asked the man, “who are you”?
The mysterious man said “l’m James Howlett”
Cap said “what do you want”?
Then the camera pan up to show the mysterious man face.
It was Hugh Jackman as Wolverine, then Wolverine asked, “haven't you guys heard, we all are now in the same universe”?
make it a stinger.
a long lost fallen hydra base, has a dialogue with two jailers having a tarentino like dialogue.
you then see a certain helmet on the containment unit.
it ends with alarms and "uh-oh" before we see the consequencies.
double post
Really I think Fox Studios will still be separate from Disney/Marvel Studios.
Fox will be the adult and conventional studio for Disney.
The X-Men and F4 will not become part of the MCU.
There might be some teasers or small cameos, but that’s all. They will mainly stay separate.