Canon will soon announce the RF 400mm f/2.8L IS USM and the RF 600mm f/4L IS USM. The first super-telephoto lenses for the RF mount. They aren’t stopping there.
I have been told the that two following lenses are also in development and will arrive next year.
Canon RF 400mm f/4 DO IS USM
This new DO super-telephoto lens will be the smallest and lightest lens of its kind. It’s a completely new optical formula for the RF mount.
Canon RF 200-500mm f/4L IS USM
A lot of people love the EF 200-400mm f/4L IS USM 1.4x, and Canon will be bringing us a successor. The source wasn’t sure if the new super-telephoto zoom would have a built-in teleconverter or not.