According to ESPN, NBA players from last season will collectively be getting $190 million back this month.
The money is being paid because NBA teams failed to spend 57% of basketball-related income (BRI) on player salaries as required by the terms of the now-expired CBA.
Same thing goes in the NHL by the way. Players get a percentage of revenue (57%). If it's not all spent on salaries, then it goes back to the players. So if you are one of the people who is saying that the NHL needs to get rid of the salary floor or reduce it dramatically, that may not solve things as players remain entitled to a percentage of revenue - whether spent or not. So that means for the salary floor to disappear, the revenue sharing arrangement would need to be altered.