Still no expanded release. The best music isn't even on the OST! Are song royalties the hold up you think?
One thing to consider is that Intrada and La-La Land seem to be the only labels currently releasing scores from Warner (well, Varese too), so naturally people will ask why such and such scores have yet to be expanded. A Red Planet expansion might not be considered high priority when compared to the myriad other options.
I like this score, and there's plenty (most) of it that isn't on the current CD to justify a proper release.
I'd have this down as the kind of title that LLL would tackle, as it's a modern sci-fi movie and they also released Revell's Titan A.E. not so long ago as well.