That's stuff cut from the show, however, not the full versions for all of them, or the episode tracks.
For example, Let's Just Live.
The song, taken directly from the show, is about a minute and a half, as are all the other RWBY opening themes, until you go to the soundtracks, where they're normal length. Not to mention This Life is Mine, in which case I would be sorely disappointed if it were naught but a 58 second song.