https://en.wikipedia.org/wiki/Operation_Slapshot
Here's the summary of the Tocchet gambling scandal for those who don't remember. It happened over 15 years ago and it doesn't appear that anyone served prison time for their involvement.
He has spent more time behind an NHL bench since his conviction than he did before (and won two Stanley Cups), so I'd say no one in the NHL is too concerned about it at this point.
Also, with sports gambling being legal in the States now, I don't know if what he did would even be illegal now.