Recently, a rumor surfaced online that Sony plans to implement backward compatibility with PS3 on the PS5. Now, this has also been reported by well-known journalist and insider Jeff Grubb.
According to him, the last time he heard about it was at the end of 2023. Thus, the development of a PS3 emulator for the PS5 seems to be ongoing, although Sony has not officially commented on the rumors yet.
It is possible that PS3 games will be released on the PS5 sequentially through the PlayStation Plus Classics catalog, as is the case with PS1, PS2, and PSP games.
As an example, one of such projects Jeff Grubb mentions is Metal Gear Solid 4: Guns of the Patriots, which is still available exclusively on PlayStation 3. Full support for PS3 games on the PS5 through an emulator cannot be ruled out either.