Nah it isn't necessary. Soundcloud isn't even made for that.
If people can't source the tracks that are available out there, or rather, want my masterized versions of regular MOD format tunes, they can use something like http://www.listentoyoutube.com/
to pinch the audio
If there really was enough interest in the audio files (which so far, there isn't) I would consider hosting them somewhere for people to grab in FLAC or something.