The suggestion here is that the type of game that can thrive on a subscription service is either a small one that benefits from better curation and visibility or a live-service one that can make up revenue on the backend by charging all the new players microtransactions (the new store shelves are inside the games themselves).

I've been saying this since Game Pass launched: it encourages scummy monetization. The kind of games that come to it are going to have more and more content locked away behind microtransactions to make up the money lost by not selling copies. It's going to gradually become full of "free" to play garbage, and people will accept it because they didn't pay for an individual game outright.