While no contract announcement has been made this tweet is pretty compelling information to believe that Matthews has in fact agreed to a new contract. This comes after earlier this summer, he made it known that he was hoping to have a contract on sooner rather than later.
If Matthews and the Maple Leafs didn't reach an agreement on a new deal. Matthews would have become an unrestricted free agent on July 1st of next year. If this news is true, this is great news for the Maple Leafs and their fan base.