The Marvel Cinematic Universe seems poised to change in a few fundamental ways over the course of the next few years. Aside from the fact that the world-shifting Avengers: Infinity War will premiere on May 4, 2018, the $52 billion Disney-Fox deal could see some massive developments take place as previously unavailable Marvel properties gradually become incorporated into the MCU.
From there, the fourth Avengers movie is where things could really get interesting. Ahead of the film's May 3, 2019 release, we have put together a list of ways in which some of Fox's most popular Marvel properties could transition into the Marvel Cinematic Universe when the battle against Thanos finally comes to a head. It's not guaranteed to happen or anything, but it's still worth diving in and discussing how Marvel's First Family could be affected by this transition.
Fantastic Four - They Purchased Avengers Tower
In Spider-Man: Homecoming we learned that Tony Stark decided to sell Avengers Tower in order to permanently relocate Earth's mightiest heroes to the upstate New York installation. The buyer of the tower is never made clear, but given the amount of money necessary to purchase something as lavish as Avengers Tower, we have to assume that it is a group with resources. In that regard, it would make perfect sense to learn that Reed Richards and the other three members of the Fantastic Four actually purchased Avengers Tower for the purpose of turning it into the Baxter Building sometime during Phase 4. Who knows, maybe we will even see the cosmic storm that turns them into heroes sometime between now and the release of Avengers 4 in 2019?
Deadpool - Fourth Wall Break
If you know anything about Ryan Reynolds' perpetually smartass Merc with the Mouth, then you likely know that he's a master of the fourth wall break. Although we haven't really seen anything like that in the Marvel Cinematic Universe over the course of the last decade, there's no reason not to assume that Wade Wilson could just walk onto the screen in an MCU-based (and possibly still R-rated) Deadpool movie and simply acknowledge the transition from one studio to another. He did the same thing by remarking on the fact that he finally got his own solo film in 2016 (along with a few other barbs thrown at X-Men Origins: Wolverine) so it would be entirely within character for him to do it next to characters like Spider-Man and Iron Man.