Why assume they were going to though? too many people online just make things up and then run with it, why chase that stuff down? They've never mentioned doing anything with TLOU2 on PS5 so even this patch that unlocks the framerate was a nice surprise but telling people about it ahead of time wouldn't do anything but lead to people complaining about having to wait.
I know TLOU remastered came out about 13 months after the original game on PS3 but only a few people actually worked on the remaster, I think any upgrades that take real advantage of the PS5 would probably need more investment and that would also mean they would likely have to charge for it and we know how well the online community would take that lol.