I have to admit I have zero idea where Canon is going. I used to think Canon was fairly predictable. One flagship APS-C, one serious hobbyist APS-C, one tiny DSLR and lots and lots of Rebels at every conceivable price point; One flagship Full Frame, one wedding photographer and serious photographer full frame and one entry-level full frame. Throw in a specialty camera like the 5Ds duo to capture a niche and call it good.
Now, it seems impossible to predict where Canon is heading. Have they decided to go all in on R mount mirrorless or are they just building out their mirrorless line before effing with us by introducing some new DSLRs in two or three years to scoop up the remaining buyers who don't want mirrorless? (better not sell all those EF lenses)
https://www.canon-europe.com/pro/stories/future-of-dslrs/
Have they decided to port everything over to the R mount? I imagine most M buyers, like most Rebel buyers only ever buy a kit lens and maybe one other lens in a bundle. They may have research that shows these buyers get an M before a big vacation, hold on to the cameras for 3-5 years and then ditch them for whatever new model is out before the next big trip. In which case, those M buyers can be converted to the low cost R mount version next time around.
Will the R7 be a true 7DII replacement, or will it be more of a 90D-type model? It seems unlikely to me that they will release an R7 that is basically an R3 with an APS-C sensor at less than half the cost of the R3.
What exactly can they put into an R1 other than two CF Express slots that would warrant an additional $1,000 or so? Would they play it conservative with an R1 leaving out some of the gee-whiz technology like eye-control focus in favor of a solid but conservative workhorse in the tradition of the 1D series?
About those other APS-C bodies, could one be an SL-type super small mirrorless? Seems very possible to me.
And, don't forget that any APS-C lens would also work on a full frame R body, just like EF-S lenses do, so you could well see a full frame high resolution R body that seamlessly crops to 1:6 with the same resolution as an R-7. And, as I mentioned earlier, it's quite possible that the R-7 would include an 4/3 killer crop mode at 1:2.
All I know is that whatever happens, it will be fun to watch and even more fun to read the outrage here when people don't get the unicorns they think they will.