A prolific camera-tech leaker claims that there is a new unit called the EOS R3 in the works at Canon. It will allegedly be mirrorless, yet be quite like the 1D series in terms of looks. Therefore, the putative new premium device might be best suited to high-speed, high-action subjects, which would make a rumored debut at the 2021 Olympic Games more plausible.
https://www.notebookcheck.net/Canon-will-have-the-EOS-R3-a-new-mirrorless-camera-ready-to-launch-at-the-Tokyo-Olympics.532038.0.html