Anyone like to setup a table of features/differentiators for each camera (price, mp, fps, max video rate, dual/single card, etc)? By descending price...
R1
R5s
R5
R6
R7? (APS-C?)
R8? full frame
R9? full Frame
I get that an APS-C sensor will be great for birders IF it has a greater pixel density than the R5 ie >17mp. It could be a cut down version of the R5s given the rumour is for >2x R5 ie ~100mp. How that fits into enhanced videography is a good question. It won't be an A7Siii competitor in that case.
The smaller sensor should give a cost benefit but that would fit into a lower end version to replace the M system. Ideally, the M5ii's 32mp sensor put into a RF mount would be a good match but that doesn't fit the full frame rumour.
I think that a full frame entry level will be a great second body for R5/R6 etc.