If Sony pulls it, they pull it. GOG wouldn’t have any options, it’s not theirs to sell, they are just a storefront.
The advantage and point of the DRM-Free nature of GOG is that once you download a game, it stays on your computer even if the game is removed and made unavailable to download. And you are able to download an “offline installer” file which can be backed up and used to install the game at any point in time even without an internet connection. So buying it on GOG knowing it may be removed is still hugely advantageous.
To play devils advocate, semi-similar is true on Steam for the most part. Even though the original was pulled by Sony, you can still download and play it if you previously purchased it.
I do have an expansive offline library though, I admit. Though I’d also say that a company removing access to something you paid for is the most moral reason there is to pirate that something.
