Surprised to hear rumours of new M cameras in the pipeline. Struggling to understand why they wouldn't just release a budget R (in same way we've have the 1XXXD's sitting alongside 5Ds etc previously).
The M will always have the potential to be smaller than the R, simply due to the mount size. The M has always been sub $1,000. I do not expect to see an R anytime soon for less than $1,000.
So, M...smaller, living in the $500-$1,000 market. This is a large and distinctive market.
R, larger, living in the greater than $1,000 world.
Could we some day see a "R-s"...with a crop sensor. Sure, then then it would need lenses to match, like a 15-85, 18-55, 10-22, etc. I see Canon focusing on populating the FF RF lenses for 5-10 years before they worry about this. Especially with the M already populated.