On the NBA: perhaps so, but then the cap dropped down to 44% later on, according to your link. That's just the same thing as the NHL's make whole provision, in effect.
As for what you said about the NFL, the requirement to spend to the cap isn't germane here, and I see nothing in the link about the 47% and how you get there.
Still, thanks for the effort, but I think my point stands (at least until there's some better info on the table). And even if it doesn't, would it be so crazy for a league that makes half of what these other league's make to ask its players to take less? The fixed costs of running a franchise are likely to be similar, so if the total take is less, then the player's take should be less as well.