Gunn and Cavill both confirmed the news.

Gunn:

Peter & I have a DC slate ready to go, which we couldn’t be more over-the-moon about; we’ll be able to share some exciting information about our first projects at the beginning of the new year.

Among those on the slate is Superman. In the initial stages, our story will be focusing on an earlier part of Superman's life, so the character will not be played by Henry Cavill.

But we just had a great meeting with Henry and we’re big fans and we talked about a number of exciting possibilities to work together in the future.

Cavill:

I just had a meeting with James Gunn and Peter Safran, and it’s sad news, everyone. I will, after all, not be returning as Superman. After being told by the studio to announce my return back in October, prior to their hire, this news isn’t the easiest, but that’s life. The changing of the guard is something that happens. I respect that. James and Peter have a universe to build. I wish. them and all involved with the new universe the best of luck, and the happiest of fortunes.

For those who have been by my side through the years…we can mourn for a bit, but then we must remember. Superman is still around, everything he stands for still exists, and the examples he sets are for sure still there! My turn to wear the cape has passed, but what Superman stands for never will. It’s been a fun ride with you all, onwards and upwards.