Seems kind of odd that some sort of new attraction would be on its way for a film that hasn't been released and hasn't proven it's weight at the box office. Maybe back in Walt's day that would fly, but not too likely now.
Inside Out made
$356,461,711 domestic and
$500,966,000 foreign for a total of
$857,427,711 worldwide.
Throwing Inside Out in the Imagination pavilion or the Wonders of Life pavilion seemed like a no brainer...especially after making so much money. For now we are left with a 2 character meet and greet.
I would go into the case of Zootopia, but I can actually understand why that hasn't happened yet. We all know what's going on with the two parks it could potentially go in (Hollywood Studios and Animal Kingdom). That just seems to be unfortunate timing.
Not that anyone is asking to hear my thoughts on the subject, but I actually think a temporary (really temporary) overlay of an exisiting attraction should happen maybe a month or so before a new films release. Get the people thinking...geez, what's this new little thing going on over there. Generate some buzz for the new film.
And here's the kicker...when coming up with these little overlays, think ahead of a way to expand that films presence in the parks ahead of time.
But I'm just a simple man with simple ideas...and I guess there's a reason I'm not making millions of dollars over at Disney...
TL;DR
Have something small in the parks to generate buzz for a movie that hasn't been released yet with potential plans to expand if the film is a hit.
EDIT:
I know it looks like I just resaid what Maineiak said, but I swear I started my reply before he posted anything. That's the trouble with trying to do too many things at work