If this is a thing you toggle through website settings of your game, it should go in Web Features. Unless it’s an API member, but if I’m understanding correctly it would not make sense for every server to be able to set this.
I don’t see myself using this much, but it would definitely help games in testing. You can make this feature manually but a large amount of users dislike if they join the game and find out the max concurrent players has been reached.
But getting dislikes cuz the game’s services are broken is as bad as kicking people out xD (Might even still be an issue cuz all the connections/disconnections)