UHD 8K is 7680 × 4320. Its 16;9 and the resolution of most 8K TVs.I think they will differentiate the R1 with following:
1. 40+ MP
3. 8K video
DCI 8K is 8192 x 4320 and is more of a standard for the movie industry.
Canon offers both in the R5 and hence 45mp (8192 x 5464) in 3:2 aspect ratio
I would expect that any future 8K capable camera from Canon will have 45mp. I find it unusual that Sony went for 50mp which is potentially 8.6k native but only allows downsampling to 8k and 5.7k cropped vs the R5's( mathematically easy) 4k line skipped and downsampled 8k->4k->UHD resolutions.
For a high resolution body R5s then the next mathematically logical video step is 12k (12288 x 6480) which gives 80mp frame grabs and 122288 x 8192 for 100mp still shooting at 3:2. Rolling shutter would probably be average but imagine 10fps eshutter at this res!!
Bring it on Canon