Why would you have to have Game Pass if you own the game? The content is free regardless of whether or not you pay for XBL Gold, but I get that you already know that and are just trying to diminish its achievements with a nonsensical argument.
It's an ongoing game. There's a category for that now. And I must say, Rare has done well to support the game with free monthly content and updates. This is how you turn a game around.
More needs to be said about the fact that Xbox One controllers can be used on the XS. That's extremely customer forward of them.
Straight out of the box, returning customers will have at least 2 controllers without having to pay extra which is brilliant and needs to be commended.
Hopefully they capitalize on this by creating a bunch of couch coop games for the XS early on in the generation.