We're told that new diffractive optics super telephoto lenses are on the way, but they may not be for the EF mount.
An unknown source has told us that the 600mm f/4 DO IS that Canon showed at the last Canon Expo could be making its way to the RF mount instead of EF. The same source also claims that two additional DO lenses are in the works, and both are likely going to be for the RF mount.
None of these lenses are expected in 2019, but they may be part of the 2020 roadmap.
More to come…