Film Studios flub preservation and restoration.

I agree that it is a conundrum, I think your suggestion would be much more ideal than just letting them sit and decompose further. I don't see a reason why would not be satisfied with a properly archived film at 4k(which as you know is a higher rendering than most of the current theaters and broadcast channels will currently air) for the next 20 years or more.

I understand your point though. Once you commit to a digital rendering, and the real analog film is lost, further highest resolution rendering is impossible and you can only copy. Plus I can see how codec standards will probably evolve and change, but again there is not much we can do about that, so why not put hedge our bets and use more than one of the current top standards?

Plus, as Alex Lindsay and the TWiM guys will tell you, once you get to 4K and beyond, the improvements in performance are so marginal with each leap as to be nearly, or impossibly undetectable to the human eye.

Its kind of like music. While we might discover a standard that allows an even wider capturing of audio in a "lossless" state, there are limitations on what the average, or even the exceptional human ear can reasonably detect in a frequency range. This is why often, if we must compress, 320 kbps rendering is often suitable for most genres of music. The only form that truly suffers at that bit rate is classical and/or extreme dynamic pieces that depend upon a huge amount of headroom in the db range to explore a thematic concept more fully without fuzziness at the high end or complete loss of in the bass sub range.

I would suspect that many films will not be demanding enough on the technical side (like Harold and Maude and unlike say, 2001: A Space Odyssey) to require the absolute highest rendering possible, right?

Since you have more experience than I do in this regard, once we have the digital master, we can make more duplicate copies in order to avoid either storage failure or media degradation, right? We would just the usual backup scenarios to worry about right? And of course any changes in format standards.