So what happens to all those playing fantasy NBA?

It's interesting. I'm not playing fantasy hoops anymore. If I was still running leagues, I'd probably do something like this (assuming the majority of the league was amenable):

-reward half the prize money to the top 2 in the current standings
-allow everyone to keep their top 2 (maybe 3) players from their team that are in the 22 who will be playing, and then have a redraft
-run either a roto or total points (depending on league rules) cage match over the 16 day regular season where the top 3 teams get rewarded for the 2nd half of the prize $