It's not something that I've ever noticed in any of the SD copies (on TV or DVD), probably because there isn't sufficient resolution to notice the difference. I gather this is simply a result of how the film masters were made back then, but can anyone elaborate? How did they do fade-outs and cross fades on film in the 60s and why does it degrade the picture so?
Someone can correct me on this, but I believe this is the result of an "optical effect" (that is, an effect which uses the optical printer, including dissolves and fades outs), which necessarily results in a loss of picture quality. Basically, the optical printer takes two pieces of film and creates a dupe, and whenever you do that you lose a "generation" of picture quality.
This happens in the "zoom" shots mentioned because those zooms were not created in camera, but were editorial decisions, necessitating the use of the optical printer.
You might notice this more readily on the Blu-Rays, but you can definitely notice it on DVD as well. I remember watching my restored DVD of
The Great Escape and being surprised by the jarring difference in quality that would be apparent whenever an optical was about to happen.