Lack of capacity if complete leveling of the inside isn't done, high cost of doing said leveling, needs to be brought up to code, and Magic Eye has more capacity than the former Carnium Command theater. Magic Eye also puts it next to a ride which means more people will notice it and go to it/and or the ride.
Really an Inside Out show for Magic Eye is going to be the hook for them to invest in the pavilion again. There needs to be a non-parks exclusive IP hook for investment in park originals, that's been a thing since the Eisner days.
Tiki Room? Don't dump money into it until you can shove other birds/Stitch into it.
Country Bears? Don't dump money into it until Big Al is singing "Love is an Open Door"
Splash Mountain? Despite not being a parks exclusive IP, it basically is in the US, and it was left to rot until it became Princess and the Frog.
Things like Big Thunder, Small World and Haunted Mansion are immune to this and Test Track has a GM bill.
Let me double down here. Inside Out in Magic Eye? Harmless! It's not worse than Captain EO next to Imagination. Not worse than Magic Journeys, HISTA, and now the Disney Shorts compilation. I get why people don't want the ride part, and that isn't happening. Figment sells too much merch in parks and is still a valuable IP to Disney. Having an Inside Out anchor next door will only increase the amount of eyes ON Figment.
Nobody will shed tears if the current film went, and will be happy if anything went into the pavilion that wasn't another M&G.