You'd think that people in the film industry would know terminology better. Even gag reels are made up of exposed film. Unexposed film means literally that there is no image on it because it hasn't been exposed to light. Having been a photographer shooting on film during 20 years of my career...
I have to wonder about that statement on the "Northern Exposure" Season 3 back cover that it includes "unexposed footage." Really? It includes pieces of never shot film left over in the original canisters?
One thing you can say about Disney is they take care of their catalog assets. They may not release them, but they do take care of them. Ditto Warner, except they DO release film and TV from the catalog.
I can honestly say at this point that I'm not interested in any of these full series sets until I see St. Elsewhere, and since I probably never will see a legit release of that series, I'm done with series sets.