Stepping back, I have some observations on this topic. Three categories that most comments by most contributors fall into:
1. What I want.
2, What I think Canon should do.
3. What I predict Canon will do.
1. For me, what I want (putting aside technical and economic impossibilities), is the smallest possible pancake (anywhere in the 28-50 range). The RF 35mm 1.8 is close enough but bulkier than I'd prefer. The irritant of macro hunting might lead me to dump the RF 35 if a better redundant one came a long. I just tested the RF 50 1.2 and much prefer the light weight and wider angle of the 35 for daily family life shots (interior "street" photography).
1a. I also want some RF attention for the big whites: Dedicated adapters with matching white color, and teleconverters with adapter length built in. As well as a true factory conversion that replaces the rear housing on a big white 400 IS III with an RF mount rear housing.
2. Canon should review all the internal market data they have and we don't, and build cameras and lenses to maximize profit in the medium to long term.
3. I predict that Canon following #2 will mean little attention to EF, mostly RF lenses and mirrorless, mostly profitable L lenses to bring the pros to mirrorless (budget conscious consumers will follow and have adapters for now) with a few quality consumer lenses but nothing very cheap except for kit zooms for an APS-C mirrorless. OVF and flipping mirrors will be as anachronistic in 5 years as film was 5 years after the first major DSLR. I predict more lenses that the purists bemoan because they rely on camera corrections to provide quality. The real future magic is in the camera, not the lens.
3A. I predict that 300mm f2.8 IS III ($7999) will be an RF lens with a removable de-adapter for EF. OD is fine if that's what it takes to get it under 2000g. I probably won't buy one anyway as the gap between 200 and 400 in my collection isn't worth worrying about. Unless they can cut an inch off the overall length and let the EF holdouts live with the IS II as a parallel offering. Collapsible for storage?
3B. I predict that many comments here in the years ahead will actually offer the contributor's answer to #1 while presenting it as their answer to #2. And I'll enjoy reading them all.