Here is a new Canon patent refers to two super zoom lenses for the RF mount cameras.
Canon patent application 2022/0035144 (USA) discusses optical formulas for a 200-500mm f/4 lens and a 300-800mm f/8 lens. Other lenses discussed in the patent literature are 200-400mm f/4 and 150mm f/5 – 600mm f/6.5. These too might be for the RF mount.
See the details of the New Canon Patent for 200-500mm f/4 and 300-800mm f/8 Lenses below.