I would like to add my educated guess about this artifact given that none of the hypothesis satisfied me:
In my opinion, the shape has a relationship with flow. I first thought of water but given the fragile nature of it I then resolve to change the fluid to air. It will be freely moving on its axis or static but it will be certainly be inside a cilyndrical shaft, shaping/energising (I don’t like to use this word), altering the laminated flow of air being dragged along by temperature difference at the ends.
I once read a book that was given to me by mistake in a public library regarding ancient musical instruments and in it, the author commented on the singing statues of Egypt and how, by means of the rising sun heating particular areas of the stone, the air flow will create a sound at dawn.
This disk may be part of a more elaborated product needed in terms of air, sound and vibration.