Spalding has been the official ball of the NBA since 1983, but the NBA is going back to its roots for the 2021-2022 season. The NBA will be working with Wilson for the foreseeable future. Up until 1983 the NBA partnered with Wilson.
According to the Associated Press:
Leather used for the basketballs will continue to come from the same provider, and the new balls will keep the same eight-panel configuration and performance specifications as the ones currently used. NBA players will also have a role in approving, developing and refining the new ball, the league said.