It doesn't appear that 2018 is going to bring us any interesting new DSLRs, we're still being told that there won't be another DSLR of significance released in 2018 (An announcement is always possible).
We're also being told that the APS-C lineup is going to see some kind of a “shake-up” in regards to any EOS 80D and EOS 7D Mark II replacements. The EOS 80D is just over 2 years old and the EOS 7D Mark II will be 4 years old in September.
The source mentios that the shake-up is likely that the EOS 80D/EOS 7D Mark II duo will be split into 3 cameras with the EOS 7D Mark III being the top camera in the APS-C lineup annd two more cameras below it, one being an EOS 90D and a camera between the two.
With what we have seen recently with Canon's Rebel and EOS M lineup, I think there's always a possibility of more sku's appearing at other levels of the product catalogue.