The Avs superstar was clearly unhappy with Bruins center Erik Haula on the draw, thinking that he either deserved a penalty or, at the very least, deserved to be waived out of the faceoff dot. Needless to say, no matter how unhappy MacKinnon was, you can't do this:
If the NHL views this as abuse of an official, the penalty is an automatic 20-game suspension. There are subsections of the rule that can knock the penalty down to 10 games or even 3 games, but I don't think there's any question that this was intentional.
Given what we just saw with Boston Bruins winger Brad Marchand and his actions on February 8th against netminder Tristan Jarry, MacKinnon's suspension is likely to exceed Marchand's 6-gamer. That's not really speculation as much as it is common sense. Marchand's actions were against a goaltender in full equipment. MacKinnon's slash on the leg of an official was both deliberate and unacceptable.