Whatever they put in the Stitch spot, it would be nice to have an original ride concept instead of another IP based attraction. I can't remember the last time a Non-IP attraction was added.
It's going to be difficult to put in a *ride*. Recall the size of the theater, there were two of them. That would be the total amount of space for a ride and maybe the pre-show lobby. If ever repurposed it would likely be another theater experience.