And as soon as that can't be the case anymore and the timeline divergences can't be ignored, they'll just write off Logan as an AU.
And? So? Continuity is nice, but I'm bewildered by the attitude of some modern fans that it's the sole, exclusive standard for judging the value of a work of fiction. If you can tell a compelling story that isn't tightly bound by prior continuity, then that's what you do, because the primary goal of storytelling is to
tell stories, not to play continuity bookkeeping. Heck, Marvel has always taken a flexible approach to continuity, especially with its sliding timescale and its constant retconning of period details (e.g. Tony Stark was originally injured in Southeast Asia, now it's Afghanistan) as well as origin-story details (hey, Pietro and Wanda are Magneto's children -- no, that's a hoax -- no, it's genuine -- no, it isn't -- yes, it is -- no, it isn't).
As I've been saying, the differences between the Fox and Marvel approaches to their film universes are a good thing. It gives them individuality and variety, so it's not all the same thing. The X-Men films have always had a flexible approach to continuity, with later films disregarding problematical details in earlier films or ignoring throwaway versions of characters in order to do their own new versions (e.g. Angel, Emma Frost, Deadpool, Jubilee, or Caliban). And after explicitly creating a new timeline in DOFP, they seem to have embraced the idea that their films represent a multiverse. That's what the producers of the upcoming
The Gifted TV series are saying, that their show is in an alternate timeline of its own, sharing concepts and background elements with the films but with events unfolding differently. So it's no longer a relevant question which is the "right" or "real" timeline. They're all "real" within the cinematic multiverse. And that helps distinguish the Fox Marvel franchise from the MCU, where everything's supposedly in a single continuity even when the movies and TV shows do their own separate things and largely or totally ignore each other.