What comes of this?
The NFL has already settled their lawsuit with the former players. Probably nothing.
This is all information that would have likely come out at trial if the case had actually gone to trial.
The only way the NFL would have a case against SI or ESPN is if they can prove that this isn't true. But it probably is true so nothing happens.
The only other way I could see something coming from this is if by ESPN publishing these excerpts of this book they are in breach of their contract with the NFL. But you would need to know what is in their contract with the NFL which isn't going to happen.