ツイッター　XBOX公式

Correction: To date, we’ve spent over 100K hours testing your favorite games from
Xbox One, including existing backward compatible 360 & OG Xbox games, on Xbox Series X.
While we are still in the process of validating, we can confirm thousands of games will be playable at launch.

XBOXONEのゲームがすべて遊べるかという質問に対して