There is a strange, irrational assumption among us rumor mongers that an R1 camera would move the 1 series into a higher resolution class. I see no reason this would be true.
This also means that an R5 II and an R1 would not directly compete if launched at the same time. In 2012, they revved the 5D and 1D at the same time. But don't take this observation as an optimistic assessment. It isn't.
I think this R5 firmware upgrading business smells like a 7D-Mark-II-scale product delay. I hope I'm wrong, but the time they specced these new software upgrades was likely in early 2022 at the latest. You can read that in one of a few ways:
1) The R52 is delayed, but they have a lot of firmware goodies from that project, some of which can exploit the old hardware, so they're stopgapping the market with an upgrade. Upshot: delay and firmware upgrade.
2) Canon realized late that their original R1 (called the R3 today) was problematically behind the new Sony and Nikon flagships, particularly in resolution. The combination of the new Nikon with a superior selection of actually-newly-designed and cheaper superteles was particularly painful. They rebranded the camera to the R3 and re-specced their next R1 effort upward and outward (~2026). Because the 1 won't ever be a high-res body, they hope a re-specced R5 Mark II will fill that gap roughly between then and that R1 release.* Upshot: delay and firmware upgrade.
3) Canon is putting finishing touches on an R5 Mark II, and just feels generous with redundant firmware upgraded development. World peace imminent. An outbreak of rainbows and unicorns infests earth, solving hunger with overproduction of pink cotton candy. I eat my hat. Upshot: New R5 rev in 2024.