Anthony Russo shared with Empire, "Endgame was the end, and it took a little time for us to begin to think about it as something other than an end. We're very close with Kevin [Feige] and Lou [D'Esposito, Marvel Studios' Co-President] and the entire Marvel team and we've had conversations through the years. We've talked about a lot of ideas. Really what happened was, we ended up stumbling upon an idea that activated all of us."
When Fox put together the first X-Men movie, discussions arose over whether moviegoers would be put off by the comic's more ‘silly’ elements. They instead opted for a darker aesthetic inspired by The Matrix.