Never tried the RF, probably never will; but one of the most interesting things on paper, at least for me, is the shortest size in the bag, and the lighter weight on a long wedding day.
Bur on the other side, I would find pretty frustrating the lack of TC compatibility.
So probably the best move for Canon could really be having a second line (maybe a 70-180 or 70-210 just to differentiate a little) which features the internal zooming, for people who likes that most, and also sporting the the TC compatibility.
If this move will help having more RF 70-200 "Mark I" on the used market for cheap, well, I think that's only positive, maybe in 10 or 15 years I will be able to afford it ahah; but for now it's a no go, my non-IS EF version is tack sharp, while being my least used lens, and on the used market I only can get 400/500€ for it, that's too much difference to cover to reach the RF lens that would see the least usage of me, too.