When Chabot signed his contract the expectation was that the cap would continue to rise a lot in the next couple of years. That's not so certain anymore, so perhaps his contract is where those guys will look to land rather than being a springboard.
Yes, Makar could wait until the end of next season, but he could also play it safe (in uncertain economic times) and take a good long-term deal to secure his financial future early, just like Girard did recently.
I mean, if he gets offered $9m x 8 years ($72 million) it would take some pretty big cojones to turn that down for the chance of making ~10% more over the length of the contract - while in the meantime running the risk of a number of things that could derail (eg. injury, cap dropping, societal economic upheaval, etc).