Apart from retheming the ride with Inside Out characters, I don't really understand why a new Inside Out film for the magic eye theater would increase the odds of a ride overhaul.
There have been several different rotating shows in that theater since the pavilion opened. None of them have ever had any major connection to the Imagination ride itself. Magic Journeys was used as a theme throughout the pavilion, but otherwise had no connection to the ride. It was also later moved over to the Philharmagic theater after Captain EO took over. Captain EO also had no relevance to the ride. Nor did HISTA apart from a couple of photos and names in the queue and backgrounds.
What is stopping Disney from cheaping out and putting an Inside Out movie in the theater while continuing to ignoring the ride? If Figment still sells his plushies anyway, then what incentive is there to do anything with the ride? Outside of again just making it an Inside Out ride and giving up on Imagination entirely.