That's what I thought too. But then again, there's no "The Starcraft Band" which could record a new master. So I think that in the case of video games soundtracks which are not attributed to specific artists, "remaster" becomes a bit of a fuzzy term. You mention remix, but it could also be a cover or it could be accepted as a remaster (if it would be something official).

All of the above, including my original question is just curiosity and not meant to diminish the effort put into creating the audio tracks.