While I cannot speak directly for Hold-Me, I can state that none of the texts DJS cites state that the snake from Genesis 3 was held to be a factual and historical account.
Also, Christian theology through the centuries shows that the belief in “Satan the Devil” was a new revelation from Jesus of Nazareth who connected the symbols of the adversaries of Scripture to evil unseen forces battling against humankind. This is a technique known as “midrash” which is still used today by Jewish rabbis. It is a retelling and resetting of Scriptural stories, whether true or false, in the light of current thought. Word play is heavily employed in this technique when speaking in the original Hebrew, and an etymological methodology must be employed when attempting to reconstruct the meanings therein. Face-value readings are never implied or allowed in midrash, especially in the face of a doctrine that was clearly in developing stages in the first century.
Around the time the New Testament canon was being settled, St. Gregory Nazianzen, working from and building upon current Christian theology about “the Fall,” taught that the narrative in Genesis 3 was symbolic of something far more complex. The death of the characters in the play symbolize God’s killing of death, he explained. This didn't contradict the then accept doctrine of the Evil One now in full stature in the Christian religion, but it does show that their belief that the Devil was real and symbolized from the protoevangelium did not rely on the symbols being facts.
Similarly, the tales of George Washington chopping down a cherry tree, the mythical details of the midnight ride of Paul Revere, and the various tall-tales which practically deify Abraham Lincoln do not keep thinking and reasoning Americans from remaining patriotic and supporting their country. All cultures have their mythology, but those myths are used as transports for essential truths important to the culture that devises them. George Washington may not have chopped down the cherry tree, but the truth in the myth is still real: he was a man of high character. The fact that these stories are just "fairy tales" doesn't make people pack up and leave America or abandon democracy. Americans still build upon these legends to create realities in their lives regardless.
In the same manner, while New Testament theology builds upon the midrash of “the satan” figure as a literal spirit entity that is bent on causing more than a little trouble for humans, it isn’t saying that the literal figure makes some of the narrative dramas fact. Nor does it mean that the use of “the satan” from Old Testament sources via midrash implies that “the satan” in places like Job is the same figure as the Satan of New Testament texts.
The above isn’t new theology or new views on Scripture and the devil either. It is theology that the uneducated leaders of the Watchtower ignore and keep from their adherents. While I don’t expect that atheists have to be totally educated in an academic approach to Scripture, these very few points should at least make one pause before projecting the naïve Watchtower approach we once fatally trusted in to what scholars and theologians of Scripture have taught for centuries. They are very much not the same thing.