The EOS R is a 30 megapixel (6720 x 4480) Full Frame camera. If you use an adapter to mount an APS-C crop lens like the EF-S 10-22, the camera will automatically turn into a 11.6 megapixel (4176×2784) crop camera (and 10.1MP on the EOS RP). It will not give you a Full Frame 10-22mm field of view. It will look like a 16-35mm FF equivalent.
I wonder what would be resolution images produced with EF-S lens on an upcoming Canon EOS R5 body with supposedly 40 MP sensor.