I really miss the Soundtrack Goodies in the recent Star Wars Releases :(

That's purely a license problem, because LucasArts and/or Disney don't own the rights to the movie soundtracks (Sony Classical does), so they are not allowed to release them outside of the games. In fact they had to license the soundtracks themselves to be able to use them inside the games.

Regarding the games that have original soundtracks (like X-Wing, TIE Fighter, Dark Forces), they usually still contain melodies by John Williams, thus can not be released either. Apart from that: There have never been official soundtrack releases for those games, and I doubt that GOG is willing (or legally able) to include fan-made soundtracks with their games.

An interesting counter-example are the Harry Potter videogame soundtracks: Inside the games they did include some of John Williams' themes from the movies (especially Hedwig's theme), so the respective soundtrack releases of those games had all the Williams material edited out, so that they were legally "clean".