Let’s get this out of the way right up front: the new super-secret X-Men project from comic scribe Brian Michael Bendis and Deadpool director Tim Miller probably won’t actually be called “143.” If anything, this is a production placeholder while studio heads figure out a catchy title (mostly likely with a colon and/or an adjective in it), but that's not saying there's no significance to the project's working title.
The most obvious reference to would be to Uncanny X-Men #143. The issue, by Chris Claremont and John Byrne, tells the story of Shadowcat (Kitty Pryde) being stalked by a N'Garai demon from the Limbo dimension during Christmas time in the X-Mansion. You know, that ol’ yuletide tale. The issue basically rips off the plot of Alien, but serves up a fun little story in the process, and has thus been fondly remembered by fans.
The fact that Bendis and Miller's project is believed to be a Kitty Pryde-centric story helps lend some credence to this theory, which if true, is kind of adorable, but might be a little too on the nose. Maybe the reference will have nothing to do with the actual story from the issue, but is instead a callback to the irony of having a Jewish superhero fight a literal demon in what is essentially a Christmas special issue. Or maybe this new X-film will follow in the footsteps of the now delayed New Mutants movie and embrace the horror elements that were prevalent in many issues during Claremont's run as the characters' main writer.
OR, maybe “143” is coming from somewhere out of left field. Maybe, just maybe, it’s a reference to Grant Morrison’s New X-Men run. This theory is a stretch, but the X-Men films have not yet introduced Fantomex, who would be a nice addition to the cinematic version of the franchise. After all, the X-Men films are quick to lean into the weirdness of their source material (just look at that timeline!), and boy, Fantomex’s backstory is about as weird as they come.
So what does “143” have to do with Fantomex? New X-Men #143’s cover does feature Fantomex looking awesome, but the most significant thing about the issue is that it introduces the character of Ultimaton, an anti-mutant supersoldier designed by Weapon Plus. Ultimaton isn’t the most well-known villain in the X-Universe, but he is pretty scary. Also, the X-Men film franchise loves revisiting the Weapon X program in any shape, form, or fashion. So his (its?) inclusion might not be completely out of the question.
Perhaps “143” will combine the stories of Uncanny X-Men #143 and New X-Men #143. Instead of a Limbo demon (which is not as fun as it sounds) hunting Kitty, it’s Ultimaton. This would certainly give the film a Terminator vibe (side note: director Tim Miller is actually working on the next Terminator film, so…), which might be more fun to homage than Alien, not to mention more fitting to the cinematic X-Universe. Fantomex could even be the Kyle Reese character of the story and… wait, did we just pitch this movie?
In the end, whatever angle “143” takes on a Kitty Pryde story (if that is where it's going), we’re happy to see it come to light. Brian Michael Bendis cleary loves the character and knows how to splice plot elements from existing stories to make a compellingly story that feels new and exciting, while also being comfortably familiar… kind of like dinosaur-shaped sugar cookies during the holidays.