Oh, make no mistake; prior FS games have no modding support. In fact, they encrypt the all game files with RSA nowadays (which is awful for read speeds because RSA is slow but whatever). Current modding support is based off of a robust reverse engineering community that’s documented most of the file formats and a significant portion of the important code. And that’s while contending with Arxan which, while not as awful as Denuvo, still impedes RE. They’d basically have to implement something as draconian as Denuvo to make things more difficult than they are.
I’ve worked closely with the people that do reverse engineering and such for FromSoft games and I can damn near guarantee that any PSN requirement would be ripped out pretty quickly. At worst they might tie it to online features. My real worry is exclusivity, timed or otherwise.