My thoughts:
EOS RP will be available for 999 come Black Friday
Don't think Canon will bring a lower-priced / lower specced FF MILC anytime soon.
I don't expect them to ever bring APS-C sensored R model/s
Next in R series will be a hi-rez EOS "RS" - 5Ds/R replacement, possibly August announcement
Then, just in time for 2020 Tokyo Olympics a duo of 1DX III (DSLR) and EOS "RX-1" -> Sony A9 (II) competitor. They can and will not leave mirrofree FF sports segment to Sony. And there are probably still enough conservative DSLR friends around in that segment to warrant 1DX III, but it will be the "final" DSLR.
Also in 2020 i expect a EOS "R Mk. II" - specced like and instead of a 5D V
APS-C:
next up M5 II - Fuji XT-3 level, but lower price, maybe aggressive 999 body only
possibly also an "M7" - as a "best in class, fast fps APS-C MILC", instead of 7D III
then "M50 II" or similar plus "M110" entry level, since it is Canon, there might be 5 different models, ever so tightly mico-marketing-differentiated, some also available in colors like piglet pink, fake gold, street-snow white and puke-yellow