I seriously thought they were leading into Apocalypse back during the third film. It had all the same plot points as the one from the TV show. The cure, Arcangel, Rogue debating whether or not she should get the procedure done, the debate. I went through that whole movie just hoping it would end with an Apocalypse cameo.

I'm just glad that they're starting to adapt actual stories from the comics now. Not sure how much they stuck to those stories in the older movies since I'm not an X-Men expert on that and it was during an era of their story I wasn't familiar with.