That's not a monopoly though based on release date. All games and movies have street dates and when mom and pop stores violate them they can get themselves in trouble with the company where they get fined or don't get any more movies and games to sell.

The actual release date can also be suggested by the NFL. I know for baseball games mlb does not allow them to release any earlier than the first Tuesday of March. The actual nfl influences quite a few things in game development.