They have filed patents before that sounded impressive yet the result we've ended up with on PS5 is PS2 games running in 480p with missing music. I'm not optimistic.
The AMD Zen 2 CPU the PS5 uses is too slow to run most AAA games in RPCS3 at full speed. We can see that an AMD 5700x can't achieve target frame rates in lots of games like Red Dead and God of War 3 even when over clocked to 4.3 Ghz and given how Sony has already fumbled the bag with their PS2 emulation on PS5, getting PS3 on PS5 is completely unrealistic.