I don't know much about the subject either, but I believe early generation material probably represents filmmaker intent better, since that's the level of quality they compose their movies in. If we are interested in color timing as well then the final answer print might be the movie. Even with an effect-heavy picture like Star Wars, where generational loss could help cover some "problems", the filmmakers would probably prefer a clean, highly resolved image that could be projected large.

Also, the Negative1 project might actually show more than what viewers in 1977 could see in theatrical showings because I believe their Telecinch device's focus is more precise than that of a regular movie projector.