The Galaxy S21 series is right about six months away from launch and leaks are already starting to surface. The most recent one concerns the S21 Ultra's main camera, indicating that Samsung will eschew other critically acclaimed sensors in favor of an updated version of its existing 108 MP offering.
https://www.notebookcheck.net/Samsung-tipped-to-stick-to-its-guns-with-the-Galaxy-S21-Ultra.488651.0.html