I'll check with the team about being able to download them. It's something you have to set manually on each track when you're uploading them, which is an enormous pain. My guess is it's just an oversight.
Thanks for listening and caring about the music, everyone! This season's music has been one of the most interesting and diverse in the history of the game, in my opinion. I'm always curious how the community will react when the boundaries of what "Guild Wars music" is get pushed, so thank you for being open minded and enthusiastic.