I'm betting we'll see three new R-series in 2022. Two will be APS-C: an R7 (mirrorless 7D. Mark II) and am R50 (beginning of the transition from M-series to R-series). The third will be a high end, pro full frame R1 with a huge sensor (75-85MP) and integral grip (like the R3).
The R7 will be a sports action camera, probably around 24MP with state-of-the-art AF, very fast frame rate, and with build, sealing and durability similar to 7DII. It will have a stacked or global sensor to avoid rolling shutter problems. And it should cost $2000 or a little less. Why 24MP? There are some things, like very fast, high volume sports photography where you really don't want the largest possible files or the camera shake issues that come with ultra high resolutions (90D and M6II have the most pixels per square mm of any interchangeable lens camera currently on the market). A more modest resolution also can be helpful for low light/high ISO work. Also, 7DII is durability rated for 200,000 shutter actuations, while 90D is rated for 120,000 clicks (up from 100K in 80D). This is important when a camera has ultra high frame rates. Another possible solutuon, Canon may choose to eliminate the mechanical shutter entirely (as Nikon has done in the Z9) if their stacked sensor in the R3 works as well as expected.
The R50 will be more video and vlogger oriented, which I don't know enough about to predict resolution. Maybe 32.5MP like M6II? But it needs to be compact (no EVF or accessory EVF?) and reasonably affordable at around $1000.
Those two APS-C models would meet the majority of market demand and they can add more models later.
P.S. Don't expect there to be an EF-M to RF adapter. The EF--M mount uses a a shorter lens register than the RF mount... 18mm vs 20mm... which makes an adapter impossible or at least impractical. There's simply no room for rhe adapter, like there is for EF (46mm) to RF (20mm). Of course, it's possible to put optics in an adapter to correct for the problem with the EF-M lens register (distance from the mounting flange to the sensor, at which all lenses for the mount are designed to back focus). However, adapters with quality optics are very expensive and ones that are more affordable typically ruin image quality. So someone with EF-M mount lenses should plan on trading them in when they buy an R-series camera or just keep an M-series camera to use the EF-M lenses upon.