alt Hacker NewsNeither the article nor the backing paper discussed made any such definite claim.
Many casual readers confuse statements such as
"which *may* have had symbolic or ritual significance."
Attribution of potential cause of inferred behaviour to "ritual" is a long standing practice in archaeology; it's code for "we don't know" and covers all manner of things that may simply have developed as habit over years, may have unknown and non supernatural causes / motivations, etc.
Ritual may also have practical/non-supernatural motivations that were simply incorrect. We do lots of things that we think are good practical things that, years later, we learn were mistakes. Uranium and radiation as a cure-all was a mistake. Dig up a 1950s house and one might think the uranium devices were kept for "ritual" when in fact they were kept for thier mistaken health benefits.