Remember, this game ran during the time between the 3rd, and the announcement of the 4th, where no other POTC movies were being anticipated. Therefore, if they stopped filming POTC movies, then the movement of the game would be.. well, pretty much the same.
Remember, the only part of the game that has to deal with actual movie elements, is a few locations, a few characters, and a few enemies. Other than that, this game is solely fueled on ideas made by the devs. So, if POTC movies cease to exist... it would probably be a really long time before POTCO did too.