Dark Phoenix’s only distinctive quality, really, was that it was sold as the conclusion to the convoluted saga first launched by 2000’s X-Men. But audiences just engorged themselves on Avengers: Endgame, the concluding film in the far more popular (and internally coherent) Infinity Saga within the Marvel Cinematic Universe. So Dark Phoenix — the fourth superhero movie this year after Captain Marvel, Shazam!, and Endgame — likely ran into some significant superhero fatigue.
Finally, the studio that released Dark Phoenix and every other X-Men film, 20th Century Fox, was just bought by Disney, bringing the film rights to the X-Men back to Marvel Studios. That makes it likely that in a few years, Professor Charles Xavier, Magneto, Wolverine, Mystique, and Jean Grey will begin to weave their way into the Marvel Cinematic Universe — so why bother buying a ticket to a lame duck franchise when a fresh take is already on the horizon?
Ostensibly the final movie in the current X-Men saga, Dark Phoenix is out this weekend to somewhat lacklustre reviews. There’s one major beat fairly early-on in the film that some fans will already know about; after it was alluded-to in trailers (such as the one above) and also mentioned in some interviews. But it was still awkward in Kimmel’s studio this week when he let it slip.