how does forgoing a long-term extension for a medium-term one hinder future cap flexibility? It only opens up more potential flexibility.
Do you guys think the Leafs wanted to sign Tavares for 7 years into his mid-30's? Of course not. A 5 year deal expiring this summer would have been much better. But the competitive nature of free agency pushes teams to make longer commitments than is optimal.
If Matthews signs medium-term he's giving all his prime years to the Leafs. And the team has an out so they're not saddled with a possible anchor like if he were to sign for 8 years. The guy has had trouble staying healthy in his early 20's, if he's not insisting on max term that's simply a gift.