Maybe a dangerous assumption, but doesn't this still benefit games with variable frame rate?
The way I think it works is that a game simply can't have two different frame rate caps, ie 30fps and 60fps.
A game like Battlefield 1 is locked at 60fps, with the regular PS4 dropping to 45 (or whatever the amount is) at times.
On PS4Pro, the game is still locked at 60fps but thanks to being more powerful will hit that more of the time (or even be always locked on it)
Surely this is the way it's happening? Would be bewildering if PS4pro users would be forced to have frame drop parity.