Given that Atlus previously confirmed that there is no upgrade path for Persona 5 Royal on PS5 – if you own the PS4 edition and want the PS5 release, then you have to buy it again – there probably wasn’t much hope of seeing your save files transferring over.
Persona 5 Royal Remaster is scheduled for release on PS5, Nintendo Switch, PC, Xbox Series X/S, and Xbox One on October 21, 2022.
The original version of Persona 5 was released for PS3 & PS4 in Japan in September 2016, and was released worldwide in April 2017. Persona 5 Royal followed in 2019 for PS4 in Japan and 2020 in the west.
If you aren’t familiar with both versions of the game, Persona 5 Royal includes additional content such as a new story, the Third semester, which includes new characters such as Kasumi Yoshikawa and Takuto Maruki.