>>3442706>What is the point of the Canon EOS M line?EOS M bodies can be made significantly smaller than RF bodies (and, obviously, EF/EF-S). Pic related. And if Canon keeps the M line for APS-C and the RF line for full frame, there's a definite price-point reason for keeping M around.
If Canon releases an APS-C RF mount body and lenses, then yeah, I'd say M's days are pretty much up. If not, though, they're probably going to keep them both around until full frame sensors get so cheap that it just doesn't make any sense to buy a smaller sensor camera.