Or the PS5 gets left with an enhanced version still running in BC mode and the X|S get an actual new version.
That could be a native next-gen version, or could just be the existing version “enhanced” in some way. There’s also “a free upgrade to an enhanced version on November 11 for their respective PlayStation 5 and Xbox Series X | S systems”. It’s the base game with some extra DLC included. Or buy the anniversary edition with it included, I guess. The anniversary edition includes the 500 extra things, but you have to pay to upgrade to that version.
The special edition gets 3 bits of new stuff, including fishing (because everyone loves fishing, apparently).