So the special editions really are legally a separate thing from the originals? (And how does it affect releasing the originals?).

In other words, if RETURN OF THE JEDI (1983) is legally a different movie from STAR WARS EPISODE VI RETURN OF THE JEDI(1997), why was that done? It certainly doesn't have to be done with every rerelease of an old movie. If it's to make it harder to share the profits (since it's a "new" movie that came out in 1997 and needs to get into the black all over again) that is really chickenshit.