Isnt that abit odd? I mean a Xbox One S runs games abit faster already then a normal Xbox One because of the slighty better CPU. Didnt need a patch or a boost for that. Why does the Pro need a patch of boost update for that?
For ensuring 100% compatibility with non-patched games, Sony locked half of the GPU and the clock speeds of both the CPU and GPU to the exact clocks of PS4 when running those.
Now they have removed that lock and downclock when the user enables the option, which has a disclaimer that it may break some games.
Edit: To further answer to your comparison to Xbox One S.
XB1 S has the exact same architecture as XB1, just with a slight CPU upclock.
PS4 Pro has a much more different architecture, where one part of the GPU is exactly like the regular PS4 GPU and the other part is a mirror of it, on top of higher clocks for both CPU and GPU.