This new flew under the radar but news has been popping up on social media again regarding the news posted back in 8th of August of last year.
As you can see Konami will be terminating network services for Metal Gear Solid V: Ground Zeroes on 5/31/2022 on PS3, PS4, Xbox 360, and Xbox One platforms. While the online service will end the main game will still playable offline. You can also still buy a physical copy of the game for each and install and play it. Record keeping and times though will be disabled.
Source: Konami
Metal Gear Solid V: Ground Zeroes Termination of network services