All movies in HD you buy are compressed, even if you buy a movie at a store that's on a Blu-Ray dual-layer disk (50 gig capacity), it's going to be compressed. So that goes without saying, but it will still look great. The point is to capture the Cinemax HD broadcast of the Star Wars movies in the full quality that they are broadcast at (whatever that is), and then back it up onto Blu-Ray BD-R disks (the best available HD optical disk format). If the Star Wars movies are broadcast on Cinemax at a very high video bit-rate and the movies go over 25 gig in size each, then dual-layer blank BD-R disks will be needed to back them up. But once it's done, the movies will be very safe on those disks.

As far as disk rot and such, naturally one would be expected to make extra backup copies of the disks periodically so that a flawless backup copy is always available, and that those disks would be kept in safe places and handled carefully. And once these disks get into the hands of sizable numbers of Star Wars fans, replacements could be gotten readily, if needed.