One of the more annoying parts of this to me is that, surely, a high quality version of the original must exist somewhere in the archives of the publisher, right? And if not that, surely the original footage must still be there, so one can recreate the edit frame by frame, as was done with TNG?

The good stuff is out there, just behind lock and key. You can't have it, because screw you.

It could also be that it genuinely isn't. The source code of Silent Hill 2, one of the best horror games of all time, is lost. It's clear from cases like that that publishers can't be trusted to preserve their media. We have to do it ourselves.