Are you arguing that Disney needs Harrison Ford for a new Indiana Jones attraction or that an Indy attraction can't be built if the franchise is no longer making movies? Both points are not valid either way, Harrison Ford was not involved with any of the already existing Indy attractions, and rides have opened recently from franchises without a movie in a while, Ratatouille (2007) had a ride open last year and Tron Legacy (2010) has a ride opening... who knows when. Indiana Jones is still probably more well known and popular than both those franchises and has a new movie coming out soon.