I see the full frame mirrorless offerings like this, in order of price:
Cheapskate/newbie entry level: Canon EOS RP, no Nikon, Sony A7 II old model
Enthusiast entry level: Canon EOS R, Nikon Z6, Sony A7 III
High-res enthusiast: no Canon, Nikon Z7, Sony A7 IV
Pro Sports/Action: no Canon, no Nikon, Sony A9 II
So if there are 2 new Canons coming, there are 2 obvious gaps. The top priority of these would be the high-res enthusiast model, especially with the new DSLR entering the pro sports segment. The A7R series has been a major success for Sony and attracted many mainstream customers, so Canon would want to address that urgently.
In fact, the new DSLR might mean the second one could be an update to the EOS R, instead of filling the pro sports mirrorless gap. Would love for it to be the sports/mirrorless model, but I reckon the EOS R's weakness at burst speed might be a priority that Canon wants to address quickly. And they seem to be rolling out a new generation of sensors, so that's my tip for the second 2020 release: EOS R II with new-gen sensor and higher burst speed and, possibly, IBIS.