After making such a big deal about the EOS R and the RF mount, I'd be surprised if they immediately pivoted right back to releasing DSLRs, which now even by their own admission are getting a little antiquated. It just doesn't seem like smart marketing to me. It seems like it would really confuse the market. I mean, how many FD mount SLRs did they continue to produce after the EOS 650 came out? Looking at their online museum, it looks like almost none, unless they just omitted those in the museum.
I suspect that the current lineup of DSLRs will be left to wither on the vine until a suitable RF mount mirrorless replacement for them is ready to be released. I know that it's a pretty bold statement to say that DSLRs are already finished, but honestly I struggle to see how it makes a lot of sense to come out with any new top level DSLRs and ask people to pay between $3000 and $6000 for them when they've already pretty plainly said that it's old technology that's on its way out. Even if they did make a 1DX Mark II replacement DSLR, could they really make the burst rate any faster than the current camera without getting rid of the mirror?