Unless it also comes with its own line of smaller mount and cheaper lenses I’m not understanding the need as you could just crop tighter (the R5 has a 1.6x crop option in camera) the R cameras are already smaller in form than a dslr, any smaller and they’d be cumbersome to use like the Sony bodies.
If you use this crop option in an R5 then the file is only 17mp whereas an R7 could have say a 30-35mp crop sensor.
Most people wanting an R7 plan to use it with FF telephoto lenses and RF-s versions of these wouldn't be significantly smaller as the front elements would be the same size and only the elements at the camera end would be a bit smaller.
For example an RF-s 600mm f/4 would still have a front element of at least 150mm diameter as the entrance pupil is 600/4 = 150mm.
The price would be similar to FF for L quality glass and at most a weight saving of 5%.
For people such as myself who want a crop sensor R camera for birding etc. a smaller form factor would be a disadvantage, my dream camera would be an R3 body with an aps-c BSI stacked sensor of about 30-35mp which I could use with long telephotos for birding (and also with a Metebones EF-RF speed booster I could use full frame EF glass with only a slight crop which would be a bonus)
In terms of pricing if Canon made an aps-c version of the R6 (e.g using the 90D's 32.5mp sensor) then I'd expect the pricing to be similar to or slightly less than the R6 and I'd happily buy one.
If they went all out and made a full-on pro aps-c version of the R3 then I'd be prepared to pay a similar price to the R3 as this would be the best birding camera ever made.
I'm not expecting a bargain similar to my old 7Dii , I want a significant upgrade on it and I'm prepared to pay for it.
I lot of people question how big a market there is for such a specialised birding camera but Canon (and other companies) have spent a lot of money on developing
specific eye autofocus algorithms for birds so they probably think a significant number of people shoot birds.