NBA 2K21 will be released on current-generation platforms on September 4, 2020, and while it won't arrive on PlayStation 5 and Xbox Series X until Holiday 2020, it is being built from the ground-up for the next-gen systems.
In addition, all versions of NBA 2K21 will offer a special Mamba Forever Edition that honors the late Kobe Bryant and his "lifelong pursuit of victory and legacy in the sport of basketball."
Furthermore, the standard PlayStation 5 and Xbox Series X versions of NBA 2K21 will cost $69.99 USD, a $10 increase over the current-generation platforms and that makes NBA 2K21 the first next-gen game to commit to that price point.
NBA 2K21 will not support Xbox Smart Delivery or a similar service on PlayStation 5, meaning there will not be a free upgrade to next-gen if you purchase the game on PlayStation 4 or Xbox One. However, if players purchase the $99.99 USD Mamba Forever Edition, they will get the next-gen version when it is released at no extra cost.