Why X-Men: Dark Phoenix Failed
5. The Rewritten Third Act
There has been some talk that Dark Phoenix was rewritten over concerns that it was too much like Captain Marvel - partly because James McAvoy hinted as much in an interview before it came out - but according to Deadline, that's just not true. The timeline wouldn't have fit, for a start, because it would have relied upon anyone working on Dark Phoenix having prior knowledge of Captain Marvel's plot before it came out. It's simply not possible.
But that doesn't mean the reshoots get a free pass, because the inspiration for them almost doesn't matter. It's the IMPACT of them that matters most and that's way beyond what's already been said about it impacting fan expectations. Reshoots happen all the time - in actual fact, Dark Phoenix was reshot less than Days Of Future Past.
Apparently, the third act was said to be set in space, which fits with how much Simon Kinberg talked up the cosmic elements of the story way back before we knew all that much about it. Hell, that was an exciting thing for fans who wanted Dark Phoenix to be something different and something fresh - for those plans to be scrapped for an Earth-set train heist that felt a little too similar to the train heist in Deadpool 2 was an awful revelation. Particularly because everyone was told about it before the film came out.
Again, it's impossible for any movie to really get over negative earworms and something as instantly marketable as the story that Kinberg and Fox scrapped the ending and rewrote it after making it once (which is how it was spun) is a killer.