[This article contains light SPOILERS for Logan]
Since its inception and well through its continued installments, the X-Men franchise is long been criticized for the continuity between the films - or rather, the lack thereof. Whether that has resulted in characters appearing much earlier than possible in their soft reboot, or retconning deaths of characters without explanation, Fox has done whatever they felt needed for each individual movie, rather than worry about its implications on the larger universe.
For Deadpool, that proved to be a great move, and it looked as though they would follow the same approach for Logan, giving Hugh Jackman's last ride no reason to worry about how it connects to past or future films. However, given the post-credits scene for X-Men: Apocalypse, many speculated that Essex Corp and Mister Sinister could be largely involved with Wolverine's last solo movie. The end result, however, appears to be tangential.
While speaking to CinemaBlend about the film, producer Simon Kinberg was asked about how the movie connects to the post-credits scene Apocalypse had. His response to a question regarding Essex Corp's involvement in the creation of X-23 and other young mutants was simply, "Yes, that is the implication." Kinberg further added that while Mister Sinister, the corporation's leader, nowhere to be found in Logan, they do have plans to introduce him in a future film:
"The short answer is yes. We would love to see Sinister. I think he is one of the great untapped villains in the X-Men universe, and we do have plans to introduce him into the world."
How and when Mister Sinister appears is up for speculation at this point, but with X-Men: Supernova on the horizon, this could be his landing spot. Sinister would be an odd fit in Deadpool 2, New Mutants, Gambit, or X-Force, so really Supernova is the only logical place for him to appear from the projects we know about. Kinberg is writing the script and possibly directing the next main installment, so if anyone knew whether or not the character would appear in a future film, it would be him.
What this move ultimately shows is some semblance of an overarching story behind-the-scenes at Fox. Sure, director James Mangold didn't want to use Sinister in Logan anyways, but laying the seeds in Apocalypse and planning to pick them up later on it a welcome sign for fans who want to see these movies be more connected. Now, thanks to this simple and subtle connection in Logan, that is becoming the case.
While the timeframe of Mister Sinister's future appearance is still unconfirmed, Bryan Cranston has repeatedly thrown his hat into the ring to play the role. This would be a major get for the franchise, especially if he was set to have multiple appearances. This decision would further allow for the universe to grow past just the Professor X and Magneto conflict that has been at the core of so many of the movies.
Source: CinemaBlend
