Now that I come to think about it, the Tram Tour has traditionally had a space about that size beside the tour route, for maintenance access, storage and such. It used to be where Toon Studio now stands. Could they be creating a new one?
I'm quite excited that this finally seems to be going ahead. While I'm not wild about the idea of yet another random Pixar movie jammed into the Studios Park (it deserves the name less and less each year) it looks like it'll be a cracking ride with some great theming. And a Studios exclusive, which is always welcome!