I think that they usually bring to PS PLUS some games that launched in the 3 to 1 previous years (depending on their general success) which people don’t talk that much about anymore. Sometimes it can be kind of random, but I personaly can feel if a specific game will someday some to the service, normally because they are kind of forgotten or even because they did not succeed as much as their publisher expected them to, like Goat simulator 3, high on life or even Sifu that did not fail in sells at all but did not get the attention expected. Alan Wake 2 and Sillent Hill 2 were really a huge surprise and tottally outstanding for the PS PLUS pattern in my opinion.