Unpopular opinion here, with modern AF and lightweight telephoto lenses, there's no need for a "pro" build APS-C camera from Canon. R6-series should be the upgrade 7Dii guys are looking for. R7 being prosumer/semi-pro are fine.
As for the battery grip. I just want Canon to make all battery door detachable so we can either use dummy battery or install 1st/3rd party grips.
Not necessarily an unpopular opinion – although one I don’t agree with. I think it all comes down to individual use cases. While accepting that mine may not be that large a market segment for Canon.
The 5Diii / 7Dii has been the ideal combination, pretty much exactly the same body, control layout and capabilities, with the 7Dii being a bit further ahead and faster FPS.
Having two bodies that are seamless to switch between and importantly have the same memory card configurations was ideal.
Shooting a lot of aviation and motor sport being able to have a FF body with a shorter telephoto (24-105 or 70-200) and an APC-C with 100-400 and quickly switch is invaluable.
At a push they also with some angle of view compromises provide a good backup body combination and limit having to swap lenses in less than ideal conditions.
For me a return to the 7Dii build and capabilities in the R series would not cannibalise R5 sales, as I’d be unlikely to put two of those in my bag. And although I have though about using the R5 in crop mode, it would still be short of an R series APS-C by about 10M pixels.
However the lack of a proper R series successor for the 7Dii has held me back from making he leap from my current combo. So at least in my case it’s actually delayed sales of two bodies and probably a few native RF lenses.
I was quit excited about the initial R7 announcement but combination of body style layout – memory card configuration and rolling shutter, pushed a decision to await and hope for the next generation.
Again I recognise that my use case is more limited than many peoples but across both Canon and Nikon the lack of direct replacements for the 7Dii and D500 to pair with a 5Diii D850 type body has been sadly missed by many in the Aviation community.