As long as we're listening to music via physical speakers manipulating air pressure, there will always be an unencoded electrical audio signal somewhere in the system.
Now, when we start getting DRM-enabled bone conductors implanted in our jaws...
Right! And this point is exactly why the comparison with video DRM in the article is a bit weak, because video will normally be split into a signal per pixel before becoming analog, making it impractical to access the full unencoded video signal.
This, plus the fact that most copyrighted audio will be playable and copyable through unprotected channels for a while (Spotify / YouTube on PC / Android) I don't think this move has anything to do with DRM.
As long as we're listening to music via physical speakers manipulating air pressure, there will always be an unencoded electrical audio signal somewhere in the system.
Now, when we start getting DRM-enabled bone conductors implanted in our jaws...