Neither 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."

with meaning "this absolutely had to do with (a) religion" when no such thing is intended.

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.