The line was dropped during Orlando Bloom’s recent appearance on The Graham Norton Show (via Digital Spy).
The fact that Orlando Bloom was in the new Pirates of the Caribbean movie was one of the earliest pieces of information we had about the new movie.
As such, it would have been natural to believe that his part in the film was significant.
While it’s still possible that Will Turner will be vital to the film from a story perspective, that apparently doesn’t mean that he needs to be in the movie for very long.