While I understand why this feature is useful in discouraging and preventing theft of AirPods, Apple seems to have toggled this 'Find My'-esque activation lock switch overnight without any communication with customers. If there had been a 2 week or so lead-up to it being enabled I don't think there would have been much of an issue, as resellers would be able to implement a human check to make sure the person trading them in unlinked the device from their account.