Canon has teased the EOS R5 by affirming that this next-generation full-frame camera is indeed in development. The OEM now asserts that it will be the "most advanced" model in its category on its launch. It also plans to release new RF lenses and lens-extenders to go with the new unit.
https://www.notebookcheck.net/Canon-confirms-the-existence-of-the-EOS-R5.454108.0.html