You can still play in offline mode.
Electronic Arts (EA) recently announced that it is going to shut down online services for a bunch of old EA games in the coming month.
Looking at the list of games that will be removing the online mode (thanks VGC), we know that EA will be cutting the online access to Command & Conquerer: Red Alert 3 and Command Conquerer 3: Tiberium Wars as well as Mercenaries 2 on November 9. Note that EA will only shut down the console servers for these titles.
Moving on, EA will also close the online services for Onrush on November 30 because the number of players online has dropped to a very low level. However, the offline mode of Onrush is still available to players.
Lastly, EA will stop the online services of Mirror's Edge, Shank 2, and Gatling Gears on January 19, 2023. Keep in mind that the Mirror's Edge Catalyst will not be affected by the changes.