Yay, annual entertainment franchises! Only TV series should be annual, movies and games; not so much.
This is a horrible idea.
This doesn't quite make sense. Serials are serial. They aren't annual installments.
Serials are simply separated into seasons simply because here in the US they are typically only produced for a limited number of episodes. The exceptions are talk shows, day-time soap operas, and UK TV shows which can sometimes have multiple seasons (series there) in one year.
Seasons are more often than not annual, it takes time to film a whole season of a TV show. Just a different format and better suited for it. If it includes spin-off's, this isn't so bad, but a mainline movie every year will not be a good thing. It could become a sort of Call of Duty of movies.