There have been a lot of patents and talk about new “big white” lenses from Canon, from the RF 200-500mm f/4L 1.4x to the RF 500mm f/4L IS USM. There is also the possibility of more lenses from the design team of the RF 600mm f/11 and RF 800mm f/11. Canon has admitted to more lenses like those coming in the future.
For now, we have been told that a “popular” super telephoto lens will get an RF mount and a completely new design. Unfortunately the source didn't divulge the exact lens that we can expect to see announced in the next month or two.
If we had to guess, both the EF 200-400mm f/4L IS 1.4x and the EF 500mm f/4L IS USM II need RF equivalents.
More to come…