Update: As
Ars Technica points out, the "Ultra Accessory Connector" is a new name for an existing port that's already used in digital cameras and other accessories.
Apple told
Ars Technica that the port has been added to the Made for iPhone program at the request of licensees, not because it is trying to push accessory makers to adopt a new type of connector.
Similarly, sources told
The Verge that Apple has no plans of replacing Lightning or using this port on any of its devices -- it will be used as "an intermediary in headphone cables."