But the thing is, just because a new 1997 or 2004 copyright is registered, the old ones don't go away--otherwise, Star Wars would revert back to Fox or become public domain and you'd have video re-issues of it in any case. So the new copyrights exist alongside the original copyrights, or they become merged into one. I'm seriously contemplating asking an entertainment lawyer about how this actually works.

The Marcia Lucas thing may have some truth to it in the sense that she probably received a portion of Lucas' gross points for SW but only for the 1977 version, but I can guarantee you that has absolutely nothing with why Lucas made the SE, it just might be an added bonus (if true).