It's clear now that the NFL had all of the information in its hand when they suspended Ray Rice. The collective bargaining agreement with the NFLPA forbids the NFL from changing the length of a suspension, if the league had full knowledge of the situation at the time of the ruling.
The league is claiming that the video changed things (which is bullshit, in and of itself, but that's another story) and at that point they extended the suspension from 2 games to indefinitely.
Will the NFLPA fight the league on changing the length of Rice's suspension? No one wants to fight for the cause of reducing Rice's suspension, but there is good reason for the NFLPA to be very upset.
ETA: The league has not formally passed on the new suspension to the NFLPA. Shortly after TMZ released the tape, the Ravens (who clearly knew the whole story, if the league did) cut Rice. Maybe the league just imposed its new suspension thusly...