When these types of studies refer to symbolic or ritualistic behavior, they generally just mean, we don't know exactly what these were being collected for, but there most likely was a good reason.

However, they note that the rest of the practice was done elsewhere and the bones do show that teeth and other things were extracted before being brought into the caves.

"The scarcity of post-cranial elements, teeth, mandibles and maxillae, along with evidence of anthropogenic modification of the crania (cut and percussion marks), indicates that the carcasses of the corresponding animals were initially processed outside the cave, and the crania were later brought inside. A second round of processing then took place, possibly related to the removal of the brain. The continued presence of crania throughout Level 3 indicates that this behaviour was recurrent during this level’s formation. This behaviour seems to have no subsistence-related purpose but to be more symbolic in its intent."