One spec doesn't make sense in regards to the R10 being a rebel/m50 replacement - the 15-23 fps. That high a fps makes me wonder if the R10 is the 90D mirrorless replacement and the R7 is going to be very high end. On the one hand it seems odd to release two crop cameras that are mid to high end and both with high fps for action possibilities. On the other hand, Canon has stated that they are concentrating on higher end users no doubt because they are the ones who buy the higher end ($$$) lenses.
Just looking at sales figures on Amazon, Rebels and M50 cameras with various kits are always among the best sellers. So, perhaps Canon doesn't feel the need to replace them just yet. I think eventually we will see rebel crop R cameras as in the long run it seem like it must be cheaper to manufacture only one type of camera and drop all the costs associated with mirrors and their assembly. The R10 might be that first Rebel replacement, but maybe it is not. Or, of course, the 15-23 fps may be incorrect, which is quite possible.