yeah, they'll work on the ps5, but you can't export ps5 saves on the ps5, just ps4 ones. maybe they didn't like the mass cheating of save wizard or something? that works even on the newest firmwares. I guess they acknowledged that ps4 saves were already tainted, and the only way you'd be able to get them is through cloud saving, which would require latest firmware and a psn+ account. sucks they have to pay for it on playstation and the switch. you get it for free on the series x, but it's very small (only 2GBs afaik).