In similar spirit, my theory is that this is part of how they fix the issue where PC players and PS5 players have issues making/accepting friend requests. Recently the players ID's were changed from being randomly generated to a set assigned ID, and I would have bet money that the PSN account linking could have been a way to resolve whatever issue was going on there.
Alas, no way to confirm this now haha!
PSN hates refunds so I can see that being a large influence.