Vision could potentially serve as the MCU's Adam Warlock, a character in the books with an Infinity Stone in his head, who's integral to the Infinity War storyline and battling the franchise's big bad villain Thanos (Josh Brolin). That would ultimately be a letdown to Marvel Comics readers who are still hoping to see Adam Warlock appear in the Guardians of the Galaxy movies, but it does keep the larger narrative simpler for Marvel.
This would mean moviegoers might be seeing Vision return in Guardians of the Galaxy Vol. 2 - where we suspect Thanos will reappear and more Infinity Stone lore will be explored. He could also be involved in Thor: Ragnarok which we already know features Bruce Banner a.k.a. Hulk as a lead character. After all, in Avengers: Age of Ultron, Thor's vision saw the realm of Asgard falling apart and the Mind Stone at the center of it.
Removing Vision from the field solves one problem of having an overly powerful quasi-cosmic character involved in Earthly matters. It also frees up Scarlet Witch - who has a romantic relationship with Vision in the comics - to pursue a more magical venture, perhaps even teaming up or training with Doctor Strange (Benedict Cumberbatch) down the road. The MCU seems to be leaning towards more "event" style movies and team-ups so this fits the bill. Seeing Vision in space is an exciting prospect and an idea that Guardians of the Galaxy 1 & 2 writer-director James Gunn has teased for a while; that an Avenger could meet-up with the Guardians. Perhaps that's Vision's destiny.
The movie stars Chris Evans, Robert Downey Jr., Scarlett Johansson, Sebastian Stan, Anthony Mackie, Emily VanCamp, Don Cheadle, Jeremy Renner, Chadwick Boseman, Paul Bettany, Elizabeth Olsen, Paul Rudd, Frank Grillo, Tom Holland, with William Hurt and Daniel Brühl. Marvel’s “Captain America: Civil War” is directed by Anthony & Joe Russo and produced by Kevin Feige. Louis D’Esposito, Alan Fine, Victoria Alonso, Patricia Whitcher, Nate Moore and Stan Lee serve as executive producers and the screenplay is by Christopher Markus & Stephen McFeely.
Captain America: Civil War will release on May 6, 2016, followed by Doctor Strange - November 4, 2016; Guardians of the Galaxy 2 - May 5, 2017; Spider-Man - July 28, 2017; Thor: Ragnarok - November 3, 2017; Black Panther - February 16, 2018; The Avengers: Infinity War Part 1 - May 4, 2018; Ant-Man and the Wasp - July 6, 2018; Captain Marvel - March 8, 2019; The Avengers: Infinity War Part 2 – May 3, 2019; Inhumans – July 12, 2019; and as-yet untitled Marvel movies on May 1, July 10 and November 6, 2020.
Source: That Hashtag Show