I love your optimism, but it's pretty much confirmed the RF 70-200 2.8 is a zoom lens.I could be very wrong, and also, with that beefy heavy elements, zoom lock is required even for internally zooming lenses. But still hoping on: "if true"
Let's wait and see, it's around the corner.
Two things that I think this will mean
a) It could be cheaper than the EF 70-200 2.8 IS III (Doesn't mean it will be, that's down to Canon, but it appears to be a *cheaper* lens to produce based on design & number of elements)
b) It won't have any recess for working with any future RF teleconverter. Four options I see for future RF teleconverters
i) They will only be useable with the big whites on RF (and the 70-200 2.8 doesn't class as a big white any more)
ii) They will work with ANY RF lens because they won't intrude into the lens (unlikely - I think this would have too many optical tradeoffs)
iii) They won't bother doing teleconverters any more - because a 400mm f/2.8 lens with a teleconverter is likely to give a lower quality image than the 400mm f/2.8 attached to a very high-resolution sensor and cropping in to get your image. Only exception will be some lenses that have built-in TCs.