One thing that benefits the DSLR is that the mirrorless still have to put on a lens. If Canon can reduce the size of the rebel by 10-15%, it should be a higher IQ alternative to mirrorless.
... you're saying this because you think that Canon lenses are better than those of the current mirrorless generations? Well, don't count on that, I don't think it's that hard to create a decent zoom, and few people will put L lenses on a xxxd body. And mirrorless bodies might even have IS built-in so you don't need it in the lens and even stabilize the viewfinder unlike Sony dslrs.
So I also think that for Canon's entry dslrs, the writing's on the wall because the only difference in mirrorless bodies is that - well, they're mirrorless, meaning no optical viewfinder. And unless you're old school and rely on that, there's no inherent difference at all.