Yep. He Le'veon Bell'd the situation to the detriment of the Islanders and the benefit of himself (and by extension the Maple Leafs). Le'Veon Bell, if you don't know with all the CFL craze up north, is a runningback refusing to report to the Steelers because he wants a long-term extension and Pittsburgh isn't giving it. The NFL has a rule where you can franchise tag a player and sign them to a 1-year, high money contract. Another player in a contract dispute, Seahawks safety Earl Thomas was in a similar situation. Signed his tag, showed up to the team, and promptly suffered a season-ending injury, flipping off the Seahawks sideline as he was carted off.
You have the argument of "I know John Tavares is literally a saint who would never manipulate the Islanders into giving him the safest possible route into a huge UFA contract".
I understand the modern realities of professional sports and the willingness of a player to value a future big money contract over doing right by his former team and playing postseason hockey.
But please, you go on believing all your sports heroes are the purest angels to ever walk the earth. No player on your team would ever be selfish enough to put their own needs ahead of the team they plan on leaving as soon as they're allowed to.