I'm sure he wanted to wait and see if the Rangers would win the series. If they lost, you know the suspension wasn't getting reduced because it'd be regular season games.
But Gary found a loophole and reclassified what Carcillo did under a different violation so he'd be able to play in the Cup Finals.
I assume you're suggesting he did this all in an effort to make NY lose, considering they're a better team without Carcillo out there being a liability.
Damn you Bettman, trying to stack the Rangers with garbage players by exploiting loopholes!