MLB is the only league with anti-trust exemption. The other leagues have attempted to gain it, but failed. Also, apparently the NFL was willing to show the NFLPA more numbers than even the teams themselves are privy to.
At first, I thought the NFL dropped the ball by acquiescing to the Players' Association's demands so soon, as it would've made DeMaurice Smith & co think "hey, if they were willing to give us what we wanted so quickly, we should have asked for more." So they decertified (dissolved) the union and went to the courts in an attempt to get more concessions from the league. However, I now believe this plays right into the owners' hands. All they have to do is go to the judge and say "look. The players asked for all this and we were willing to give it to them. However, they rejected the offer so they could file an anti-trust lawsuit and get more. This goes to show they were never negotiating in good faith and were planning to do this all along." Boom. Game over, owners win.