Anthony Russo, one half of the directing duo behind the Avengers: Infinity War Saga, recently gave some insight to that very question. Speaking with SUPER interessante (translated via comicbookmovie), the filmmaker explained why mashing up the TV and movie universes isn't as easy as you would think.
"It's complicated. When we start to serialize the telling of stories it's difficult. You have to have a lot of control and focus on the course of history." Says Russo. "The films are controlled by a group led by Kevin Feige, so they function as a unit. Other products, even if they are from Marvel, are controlled by others. Then there is the possibility of a crossover, but it's more complicated." …show more content…
" It is a smaller scale version of the problem that exists when remembering that Fox holds the rights to some of Marvel's most popular characters, as does Sony and others." He says.
However he didn't rule out the chance of it ever happening, saying that Spider-Man, a former Sony property, was returned to the Marvel fold.
For now though, we'll have to enjoy Marvel's TV and Movie universes as separate entities. The next film in the series, Captain America: Civil War hits theatres on May 6, 2016 while the TV side can look forward to the release of Iron Fist, Luke Cage, and The Defenders in the near