The FDA's definition of what is or is not a medical device has nothing at all to do with nutritional supplements; those are covered by entirely separate rules. In reality this product probably is a Class 1 medical device, which is subject to only very light regulation. The FDA might decide to ignore it for a while until it becomes a larger issue. If you talk to actual FDA staffers they're trying to encourage innovation in this space by not being too heavy handed, while still protecting patients.