I saw this coming when Magic Bands first came out. With the ability to microchip your dog, it was only a matter of time before people started trying this on themselves.
I think Disney would be better served, if they instead posted a rule on their website that 'subdermal microchips will not be a valid method of entry, payment or line passing.', because someone is going to get an implant that is NOT from a Magic Band, but can be programmed to act like one.