Anthony Mackie originally signed up to a 10-picture deal with Marvel Studios. The Marvel Cinematic Universe has been a tremendous success, but it simply wouldn't be possible without multi-picture deals. It requires actors to reprise their roles across multiple films, with character arcs that run over the course of years.
Sooner or later, every contract comes to an end. Marvel recruited many of the OG Avengers under six-film contracts, which became increasingly problematic as the MCU grew. Viewers knew that Avengers: Endgame would be the swan song for the OG Avengers, simply because the contracts had run out. More recently, Marvel's been a lot more secretive about the length of the contracts they've signed actors up with, in order to prevent audiences knowing in advance when an actor was about to bow out. There have been recurring rumors that the contracts have had a quite impressive length, but these have never been confirmed.
In an interview with Men's Health, Anthony Mackie revealed that he initially signed up for 10 Marvel movies. At this stage, he's already gotten through six - Captain America: The Winter Soldier, Avengers: Age of Ultron, Ant-Man, Captain America: Civil War, Avengers: Infinity War, and Avengers: Endgame. Assuming they all count - Marvel's sometimes negotiated separate cameos, such as Chris Evans' appearance in Thor: The Dark World - he has four left. Mackie noted that he's unsure how the contract is affected by the upcoming Falcon and Winter Soldier Disney+ TV series, which admitted may complicate the issue.
Mackie's comment gives insight into just how far in advance Marvel Studios likes to operate, and suggests they always had big plans for Sam Wilson. Indeed, it's even possible Marvel had always intended Falcon to become the next Captain America, back when they first hired Mackie for the part. The current wave of Marvel blockbusters appear to be heavily influenced by the comics published between 2010 through to 2014 - Captain Marvel was heavily influenced by Kelly Sue DeConnick's Captain Marvel run, which launched in 2012 - and that was the period where Sam Wilson became Captain America. If so, Marvel Studios president Kevin Feige had clearly always been planning to push themes of diversity and inclusion, which were core to Nick Spencer's Captain America: Sam Wilson comics.
The news also likely means that the MCU will feature more Captain America movies, albeit starring Anthony Mackie rather than Chris Evans. Mackie himself insisted he doesn't know anything about this; as he told Men's Health, "I just wait for the phone call." Marvel Studios is expected to say more about their Phase 4 slate at their Hall H panel at San Diego Comic-Con 2019, so there may be news there.
Source: Men's Health
