It appears that Bryan Singer won't return in X-men franchise.

Bryan Singer is done with X-men franchise THR reports. That might be a consequence of latest X-men: Apocalypse poor box office results, as it made 200 millions less than Days of the Future Past. As far as Deadpool 2 also lost it's director this is interesting to see who will lead up a new generation of X-men movies, because Bryan Singer was working with this franchise from the very beginning and rebuild it with successful First Class(2011). 

This franchise owns Singer a lot in terms of creativity and love for it. It was also reported that Simon Kinberg will work on the script of a new flagship movie of X-men universe.

It is unclear where the franchise will go after Apocalypse, because Michael Fassbender, James McAvoy and Jennifer Lawrence are out of their contracts, but Kinberg writes a new script with optimism that they will come back. So he must make a truly great script to interest them.

So now it is very unclear how Fox will move on with their property.