See my Canon mirrorless wishlist.
When a high resolution Canon EOS R-Pro appears, the Canon RF 28-70mm f/2L looks to be a must-have lens. At about $2999 it’s out of range for at the present time*, but it does the duty of 4 prime lenses, and to a very, very high standard of performance.
I just love having f/2 in a zoom lens—super nice for focusing and for bokeh. It’s big and heavy, but since it covers 28mm 35mm, 50mm, 70mm it can be forgiven as the only 'carry' needed for a lot of stuff.
Lots more coming soon; see my in-progress review of the Canon RF 28-70mm f/2L.
* $11K of medical bills are not helping, and the prospect of buying a Canon EOS R and Nikon Z7 and Panasonic S1R, all with some sort of lenses, is just not in the cards.