Why it doesn't include it? Or, will there be a CRSIS?
Some search results show people asked about it, and you may use CMSIS' DSP on the R family, but ... There is no CMSIS "core" for the R family.
Seems a loss :( ?
Likely because CR CPUs aren't so often seen in the wild.
It seems they growing, and family expanding.
Sure, but Cortex-R is not widely used. Custom ASIC or automotive chips. And automotive likes to use their own "standards".
I know of only one manufacturer producing Cortex-R only SoCs.