That's not what's being said here. Not Sony losing rights to a game, just entirely being unable to provide proof of ownership on digital content.

I've had Microsoft do this to me for Minecraft during their transition to owning it where they claimed I didn't own the game. I had to legitimately email them a picture of a receipt I owned to get my account back. Had I not had that receipt I'd not have the game.

I've never had Sony do this but I hear they've done this exact thing to people in other ways usually DLCs.

With NFTs there's a third party undeniable proof of purchase and ownership. It takes that whole side away from the distributor giving power to the consumer.

In a better world I could then sell that NFT and proof of purchase and the company would honor it for the person I sold it to allowing for the resale of digital content.