Back when the Marvel Cinematic Universe was just 2008's Iron Man, James "Rhodey" Rhodes (Terrence Howard) was introduced as a close friend of Tony Stark (Robert Downey Jr.). War Machine, as he was dubbed, has made it through many more Marvel Cinematic Universe's movies since then, but Howard left the franchise due to a contract dispute. Howard isn't looking to reprise that role, which is now held by Don Cheadle, any time soon.
When asked by a fan if he would consider returning for another movie set in the Marvel Cinematic Universe, Howard had a surprisingly definitive (and profane) response: "You know what's so funny? Even though I love Don Cheadle so much and I love what he's done, I still hear a lot of fans asking, am I going to come back and be War Machine," Howard said on Watch What Happens Live with Andy Cohen. "Am I going to come back and be War Machine? I think they could have a huge franchise off of it, but fuck 'em."
Since Marvel Studios already has a huge franchise which includes Cheadle playing the War Machine character, it didn't seem likely in the first place that Howard would have been asked to return, but his own feelings on the matter are now entirely clear.
Cheadle's James Rhodes will return in the untitled Avengers 4 on May 3, 2019, which may determine the ultimate fate of the character as Marvel sets up its next phase of the MCU.