Reading parts of these documents makes you wonder if the SE were Lucas's way of testing the public to see if they believed as he did. Going as far as you said that they were 'a threat'.
but here's a caveat:
philosophical tastes of the copyright holder.
Although he's the copyright holder he's also the creator and might not feel that these things apply to him. The complaint at this time was Ted Turner buying movies then doing what he wanted with them. (this issue resurfaced in 2004 when the Three Stooges were colorized, and that's what brought these GL testimony quotes back into print)
The other thing which was of interest, poking around, was there were several attempts to amend US copyright in this time period and some of the revisions centered around film.
1987.03.13 - FIlm Integrity Act (Colorization)
1987.05.12 - Legal Issues that Arise When Color is Added to Films Originally Produced, Sold, and Distributed in Black and White
1988.03.03 - Berne Convention (George's testimony)
1989.06.20 - Moral Rights in Our Copyright Laws
1990.01.09 - Moral Rights and the Motion Picture Industry
Wonder if GL saw this progression of legislation, and how they used his words in the following rounds which modified his mindset. The 'National Heritage' line met with a roll of the eyes by some of the later testimonies.
zombie84 have you come across the 'National Heritage' quote which has been attributed to the George testimony? this quote:
"I am very concerned about our national heritage, and I am very concerned that the films that I watched when I was young and the films that I watched throughout my life are preserved, so that my children can see them."
Or is this turning out to be a bastardization or misquote which has taken on a life of it's own? From some of the articles of this time, GL and friends also visited the Copyright Office so maybe it's from one of those meetings. Didn't find any documentation though from that.
Was odd to find these docs, then later in the day go see Tron with a digitally created actor in younger form. (still in that uncanny valley for me, brought back Final Fantasy memories... It's Warm...) Also found a document which could be one of the inspirations for Jar-Jar! hey someone's gotta be into that kinda thing.