A lot of films raise revenue from product placement.

Star Wars has an edge over those forms of entertainment because the product (namely the merchandising) placed in the film is franchised by the author.

When the SE came out not only did Lucas get increased revenue from the theatrical run and later the home video releases but there was also unique merchandising (Ronto toys, Swoop bikes etc).

Possibly, to keep the merchandizing rights he has to extend the copy on the films, which means making changes to shift the identity of the copy.

What I don't understand is how this would effect the original cuts of the films.

If the 1977 version of Star Wars reached it's expiration date in terms of entering public domain would that include the merchandising rights if the SEs had prolonged the copy life?