NBA 2K21 servers won’t be working after December 31, 2022, according to 2K Sports. This is due to the NBA 2K21 servers being discontinued, as 2K looks ahead. Players will no longer be able to play modes in NBA 2K21 that are online-dependent. NBA 2K21 also won’t be available for purchase after the first day of 2023, according to 2K.
“Players will no longer be able to play ranked or online league games. Accordingly, any mode that earns or uses VC will be affected, along with any other online function (such as the MyTEAM mode and online matches against other players). As of January 1, 2023 this game will no longer be available for purchase. Players who already own it will still be able to redownload and play offline modes, of course.”
NBA 2K server shutdowns are regular occurrences in the game cycle and usually shut down around 2-3 years after release.