There was a separate issue with the 3.0L TDIs (which do use AdBlue) that VW had not informed the regulators of certain modes that the engine could enter due to temperature. This looks like that issue.
"Audi also shed light on the Auxiliary Emission Control Devices (AECDs) which the EPA had earlier labeled "defeat devices," confirming that the tech was part of a "warmup strategy" for the catalyst in the 3-liter emissions control system, and was thus completely different from the emissions-cheating software found in the 2.0-liter VW engines."
"Audi also shed light on the Auxiliary Emission Control Devices (AECDs) which the EPA had earlier labeled "defeat devices," confirming that the tech was part of a "warmup strategy" for the catalyst in the 3-liter emissions control system, and was thus completely different from the emissions-cheating software found in the 2.0-liter VW engines."
http://autoweek.com/article/vw-diesel-scandal/audi-develops-...