While the idea does seem enticing (I'm a big fan of the pro), it also seems like a big mistake. The Pro and the OneX had a reason to exist. Both those revisions came at a time when 4K televisions were seeing a huge drop in price and gamers wanted their games to take better advantage of their fancy new sets. This is kind of mid-cycle jump in display tech was also why so many wanted a WiiHD. Right now, 8K is on the horizon, but I doubt that a PS5 would be able to take advantage of it since they're still struggling with 4K. So, yeah, a PS5 Pro just doesn't have a need to exist. Yet.
On top of that, it will possibly create a situation where instead of seeing enhanced titles for the Pro models, we'll see downgraded titles for the standard ones. We're already seeing that with XboxOne and PS4. Doing this at the start of the generation will only further hurt the quality of base model software.
All that said, if PS5 Pro is somehow compatible with Physical and Digital versions of PS1, PS2, PS3 and (with included external adapters) PSVita and PSP titles, then I will pay up to 2,000 for it. Just kidding, that's way too much (not kidding, I would legit pay that much... like... in installments or something).