It strikes me that believing a child's Christmas fantasy is harmful shows just how difficult it is to brake the WT programing. There is absolutely no empirical evidence that belief in Santa is in any way detrimental to a child's emotional health. yet the sense of superiority the WT imparted to it's members regarding assertions like this one lingers long after one believes the programing broken.
Being unable to prove a negative one must prove Santa does not exist by proving there is no evidence his existence. To tell children there is no Santa because there is no proof of Santa wile maintaining that there is a Jesus or a god indicates a brake in the logic.
My darter asked me one time, "what is the God?" Not wanting to lie I told her "God is our shield against despair."