The NHL clearing thing is largely irrelevant, they likely don't have much of a legal position to stand on there.
But do we even know what this incident was he got suspended for? I haven't seen anything about it, so it could be literally anything. It's only one game so probably something minor, not much reason to get worked up about it. Unless we think someone like Zach L'Hereux won't be allowed in the league (who is suspended far more often than Mailloux and recently suspended for attacking a fan), then I don't think there's much to worry about.