I think your being very optimistic thinking it wont happen. PS console sales are not going to be effected by this otherwise all them people who just buy a console for Fifa or GTA etc would already own a PC. Im sure Sony have done the numbers and like i said when they talk about dev cost going up they are no longer on about PS4 games but PS5 games. How many PS4 games do they have to port?, you really think once they get done with them PS4 games they are just going to leave money on the table for a 2+ years?.
Sony have raised game prices to $70 to compensate for higher development costs. They also have a ton of PS4 games they could potentially port: Dreams, BloodBorne, SpiderMan, Ghost of Tsushima, Gran Turismo Sport, TLOU Part II, Miles Morales, GOWR, GT7, HFW, which would take a couple of years if we assume Sony is fast tracking their ports starting in 2022, already leaving a 2/3 year gap for PS5 exclusives to be ported to PC.
That's also assuming Sony will only bother porting their bigger titles, while smaller games like Gravity Rush 2, The Last Guardian, Concrete Genie, etc won't be ported at all.