On 29th July 2024, Xbox 360 users will no longer be able to purchase new games, DLC, or other entertainment content from either the console store or the web-based marketplace.
The Microsoft Movies & TV app on the Xbox 360 will stop working too. Any games purchased will still remain playable and deleted purchases can still be re-downloaded.
Online multiplayer will also remain accessible for games already purchased (digitally or physically), as long as the publisher supports the servers.
Further, users will still be able to play Xbox 360 games on Xbox One and Xbox Series X/S consoles via backward compatibility, and hundreds of games will remain available to purchase on those consoles.
Microsoft is just warning that things will slowly wind down in an ever-decreasing spiral before shutting off its life support completely will not affect anyone of consequence.