After watching the video, it seems that they are distinguishing it by the fact that it was a man-made object created for the specific purpose of producing music. This of course still allows for other pre-existing natural objects to be used for music playing.
For example, I assume prior to creating a flute, human ancestors likely batted rocks together or beat rocks against hollow logs to create a beat or variants of music.
But the significance of this finding is that it was purpose-made for creating music, which is interesting since it hints at the cultural impact that music may have played 60,000+ years ago.
That reminds me, tangentially, of The Song of the Reed, by Rumi.
(think of the 3 meanings of reed: an instrument turning human breath (life) into music, a writing tool (qalam), and of course a living creature itself)
Or just hitting something with a stick to drum