I thought this bullet point was interesting in the rumored Canon mirrorless, "Wider support for the EF lens family". Not sure what the heck that means, but it might be very important.
Sony has gone full frame with its mirrorless. For people photography professionals, full frame makes much more sense than APS-C does, at least for Canon and Nikon owners. The standard "pro lenses" are all designed for use on FX in Nikon, or FF in Canon. The 70-200 f/2.8, the 24-70mm f/2.8, the 16-35 f/2.8, all three of those Canon L-series lenses were designed for use on FF. Same with their 35mm f/1.4, and their 85mm lenses, same with the 24-105-L. The vast majority of Canon's "good lenses" were ALL designed for use on FF cameras. The Canon EF-S lenses are useless junk on their full-frame cameras...those EF-S lenses will not even MOUNT on anything but APS-C cameras! Canon has a very clear, obvious differentiation between its consumer gear, and its "pro" gear. The L-series was designed for FF bodies. The Canon "pro" lenses are expensive, and many hobbyists simply can not afford more than one of those lenses, whereas the typical professional user very often is a shooter who happens to own two, or three, or even four or five, Canon L-series lenses.
Of course, if this new camera is an M-series model, it would have its own lens mount (right?). But then again--what about that "wider support for EF lens family" bullet point? This rumor does not seem very solid to me. The reporting of this sounds very sketchy. There are some things that just do not sound legit. But the idea that Canon has a mirrorless body in development? SURE THEY DO!!! The M-series seems like a refresh could be helpful. So far, the Canon M series mirrorless has been a big, fat FLOP in North America, and a number of pieces of the system have not even been officially imported into North America: the Canon M system is probably the LEAST talked-about mirrorless of all; Sony, Fuji, Olympus, Panasonic, hell even Samsung, all of those get more mentions. Nikon's CX system is pretty much dead on the vine.
I personally think Canon realizes that the all-new M-series is not fertile ground. I keep going back to the "wider support for the EF lens family" bullet point. Not the EF-S family...but the EF lens family. I really wonder what that might mean.