I've wondered about this for a long time. Seems like a real gold mine if it were to actually happen:
Does Disney make archival video of attractions and shows before they are removed? What I mean is, for example, before they tore out Adventure Through Inner Space (or America Sings, Captain EO, Peoplemover, Country Bears, or whatever) did they take a film crew into the attraction and document everything? If they didn't do it in the early days (Nature's Wonderland comes to mind), maybe they might have started doing it at some point.
And what about the Broadway shows like Beauty and the Beast, etc.? I know they film certain scenes for promotional purposes, but do you think they've actually filmed the entire show with the original cast?
It kind of blows my mind to imagine what kind of footage is hidden away in the archives only to hopefully surface again in some future editions of Walt Disney Treasures!