2 reasons.
First, yes there is a subscription. Though you are probably still in the included trial period which I think is 3 years.
Second, the maps expire because roads change and they are constantly updating the scans. There is an update to the maps being pushed out now to Job 2 cars.
are you a job1 car that doesn't have a bluecruise but is getting a free year? Does this mean the free year begins on march 14th, and we will be getting the update then?