According to The Hollywood Reporter, John Cena has been cast in a new Transformers spin-off called "Bumblebee" which will be focused on the Transformer character of the same name. He will be co-starring with Hailee Steinfeld in the film, which is set to open on December 21, 2018. It will remain to be seen how much time away from WWE Cena will have to take to shoot his scenes for the film.
The report names Cena as playing "a lead role." However, his character is not mentioned in the synopsis given, and indeed, they don't even say what character he's playing.
"The story is set in the year 1987, where Bumblebee finds refuge in a junkyard in a small Californian beach town. Charlie (Steinfeld), on the cusp of turning 18 and trying to find her place in the world, discovers Bumblebee, battle-scarred and broken. When Charlie revives him, she quickly learns this is no ordinary, yellow VW bug."
Since the film is a prequel of sorts, set thirty years ago, I for one hope Cena is playing Mark Wahlbergg's character's dad or something.
The film is the first spinoff in what the studio hopes will be a Transformers Cinematic Universe. They'd lilke that "TCU" to include more prequels and spinoffs and why not? Since the global viewing public has decided that the first 5 movies were good enough to warrant a $3.7 billion total worldwide box office. The most recent of these, Transformers: The Last Knight, came out last month on June 23 and has already made $568.9 million worldwide.