https://wccftech.com/xbox-series-x-xbox-one-games-game-pass/

The Xbox Series X console is going to play games released on previous Xbox consoles, and it is Microsoft's intent to make the vast majority of Xbox One games playable on the new console at launch.

In a new post on the Official Xbox website, Phil Spencer confirmed that it is their intent to make all Xbox One games not needing Kinect playable on the Xbox Series X at launch. It is also been confirmed that most games will load faster and perform better on the console.