You’ll want to check your country on the list.
Microsoft sent an email out to customers today announcing upcoming removal of games from the Xbox 360 digital store. The announcement may be confusing as it is incredibly vague and the documents themselves even state that titles “may” be removed from the store.
The announcement:
Starting F?ebruary ?7, ?2023?, a limited set of games, add-ons, and in-game content will no longer be purchasable in select markets via the Xbox 360 Store. You will still be able to play discs or previously downloaded games on your Xbox 360. For more information, visit Xbox Support.
The list of games varies based on country, for which the Microsoft support page has country-specific PDFs available. The United States for example has over 40 games being removed including Assassin’s Creed Brotherhood, III, IV, and Liberation as well as Valve’s titles (Counter Strike, both Left 4 Dead titles, and The Orange Box) among a couple of Call of Duty titles.
If you own the titles already you will be able to continue redownloading them after the removal. Microsoft has not explained in any detail why these titles are being pulled.