It has been known that X-Men: Apocalypse Bryan Singer was going to prepare everything for the arrival of the movie Gambit starring Channing Tatum.
In a recent transmission of X-Men Apocalypse IGN US, the writer and director Simon Kinberg confirmed that the teaser of Mister Sinister was to connect directly with Gambit (via ScreenRant).
Kingberg explained, “We had a teaser at the end of Apocalypse. Essex Corp is reached to see on a label at the end of Apocalypse. We had talked about doing something with him, and I’m not going to go into the details because that is not a property of 20th Century Fox and is part of the MCU. I have No idea what the plan is, but Mr. Sinister was going to be part of the movie Gambit starring Channing Tatum.“
X-Men: Apocalypse brought back characters from the timeline of the “reboot”, and in addition to the Storm Alexandra Shipp, Cyclops Tye Sheridan and Jean Grey Sophie Turner, had a cameo of Hugh Jackman as Wolverine. In fact, the tape ended with the return to the facilities at the Lake Alkali when a group of men picked up an x-ray and a blood sample of “Weapon X” in the name of Essex Corp.
But although the plan was to present to Mr. Sinister in Gambit, the film was on hold indefinitely, along with other projects after the acquisition from Disney.