PS3 is near to impossible at this point. Only reverse engineering the PS3 CPU, but taking into account this new Jin about trashing their legacy.
Even the emulator for PC requires a loads of housepower and PS5/Series X struggling to run some games at high resolution and stable frame rate, besides their first party of course.
PS2 would be more believable. PS2 have a vast catalogue of games, PS2 can run PS1 games so you can both release PS1/PS2 games. If the rumors are right, Sony would fix their mix bag PS2 emulator on PS4 and even replace their horrible PS1 emulator since PS2 emulator would run PS1 games.