I have took a closer look at the PfH stream, and it seems that class preview might be in the game - in class screen there is a small button “details” right to the class’ name.
I don’t see anything of that kind for Sublcasses, but they don’t spend much time there.
Oh, good spot. I can see that, for example, at 4:18:27 in the PfH Release Showcase. I can confirm I didn't see or click that details button (dammit!!!) so it is at least possible that might be the class progression info we are hoping for.
"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"