Having the ability to regularly update attractions is a good thing IMO. I also think you may be overstating the reliance on screens in MB and other new attractions. What I see trending, at least at Disney Parks, is the use of mutiple mediums to tell a story, and that includes screens, sound effects, AA figures, practical effects, scents, projections, synchronized vehicle motion, and thematic props. Mission Breakout, Flight of Passage, Mystic Manor, and SDL's Pirates are recent examples of how Disney is combing a range of techniques on different scales.