They suspended him for 2 games, then reacted to the @$## storm and increased it to indefinite, but the league changes suspension lengths all the time. Usually shorter, but changes are pretty standard. It’s all still one punishment.
It seems that when suspensions are changed, it's because of an appeal. I'm not sure if such a thing happened yet in Rice's case.
Regardless, Rice will have a chance to make his case, and if the NFL violated the CBA, Rice could prevail.