I doubt he knew enough about Bewitched to know that much. Still, even if he did, I doubt he'd care. Harry Potter also had that people either were born with the ability to do magic or not, and his "logic" was that those crazy kids who read the books would just turn elsewhere for magic powers. He probably figured that fans of Bewitched would do the same.

Because in the world of Jack Chick, kids who want magic powers apparently don't just break twigs off of trees or shout "Abracadabra" randomly and leave it at that.