https://www.gamespot.com/articles/two-xbox-one-games-will-be-removed-from-xbox-game-/1100-6456271/

Two titles in the Xbox Game Pass library will be removed from the catalog at the end of the month. Metal Gear Solid V: The Phantom Pain and WWE 2K16 will exit the catalog on January 31. As explained in this official Xbox Game Pass FAQ, you will lose access to both games come the end of the month, so you may want to play as much as you can.

The Phantom Pain launched into Game Pass on November 1, so when it leaves on January 31, it will have been in the catalog for three months. For what it's worth, Microsoft said from the beginning that The Phantom Pain would be removed on January 31, so this was no surprise. Further still, Microsoft sent an Xbox Live message to Game Pass subscribers last week informing them that The Phantom Pain (and WWE 2K16) would be removed from the library on January 31.