I thought we had all gone over this many time before that a square sensor cannot exist due to mirror clearance issues (unless of course it is 24mm x 24mm, which would be pointless)?
in case you did not notice we just put a rover on mars.
the easiest way is to make the camera mirrorless.
and hey im not saying canon will do that im just saying it is rumored.
We do not only put it on mars :-D we put a freaking rocket powered flying crane on mars and lowered it from that
After letting it fly 563,000,000 km trough Space! Just 2,4 km away from the spot we wanted
That is just like hitting a hair 280 Km away
So let canon-engineers do there job and bring us something new!
square-sensor ? problem with moving mirror ? let it stay and make its reflectivity electronic controllable
you are skeptical about that? look at you automatic dimming rear mirror in you car ... its exactly that
just the tip off the iceberg off what is physically possible