Wow. First off, I have to take this rumor with a huge grain of salt, but I say “wow” because it kind of makes sense. The transitioning has already begun since Days of Future Past, when during the last scene in Xavier’s Mansion all of Singer’s original cast made a cameo. It was practically a farewell from the old cast.
Next, X-Men: Apocalypse will re-introduce us to characters like Cyclops (Tye Sheridan), Jean Grey (Sophie Turner), Storm (Alexandra Shipp), Nightcrawler (Kodi Smit-McPhee), and Angel (Ben Hardy). This film will likely serve as the last for First Class cast members James McAvoy, Michael Fassbender, Jennifer Lawrence, and Nicholas Hoult. Then we have confirmation from Hugh Jackman that Wolverine 3 will be his final appearance as Wolverine. It makes sense that Singer will also be the last to depart with his franchise star.
Chances are Singer’s departure won’t mean another reboot. The younger cast who are making their debut in Apocalypse are probably signed on for multiple films, so they could be the ones to carry the X-Men movies going forward.
Just thinking of the idea that Bryan Singer’s universe that he started back in 2000 is finally ending is tough. I was 10 years old when the first X-Men released in theaters, and I loved it very much. For now, this is in fact just a rumor, but sooner or later Bryan Singer will decide to end what he started.