After X-Men: Apocalypse, the main lineage of X-Men movies seems to be waning. Supernova (or whatever the title ends up being) could resurrect interest in the franchise, or it could retread water and end up a moderately better version of The Last Stand. Whatever it ends up being, it needs to not be three hours long like Apocalypse.
But that brings us to something else: the recent success of the franchise hasn’t been in the sequels, but the sidequels. Logan drew rave reviews, even in untraditional places. Legion is setting a new standard of weird on TV while hinting at a bigger story integrally tied to the movies while existing as a separate entity. Deadpool is a verifiable cult hit. After a few missteps, the X-Men spinoff attempts seem to finally be hitting their stride.
This is exactly why Sam Rockwell needs to play Jamie Madrox in an X-Factor Investigations movie.