Basically just pure specuation, but it's thought Channing Tatum may be showing up in The Flash movie.
When Rick Famuyiwa was first announced as director on the DCEU Flash movie, eagle-eyed redditors noticed the director started following Geoff Johns -- and Channing Tatum.
Obviously that is not much to go on, but it's possible with the Gambit movie getting delayed (or not happening) that Channing Tatum could be joining the DC cinematic universe.
It's guessed by fans that Channing Tatum may be playing a certain character that was just killed off in DC's Legends Of Tomorrow...
Rick Famuyiwa also happened to follow Mark Waid on Twitter, known for writing The Flash comic books as well, and Famuyiwa posted a pic of his comic book home work featuring trades from Johns' Flash run.
The Flash has a March 16, 2018 release starring Ezra Miller.