No 'S' Models on sale now

It's interesting - Audi's UK range seems to have halved since September. All the 'S' and 'RS' models appear to have been discontinued and only a limited choice of engines are available - 1 2.0 diesel and 1 petrol choice only on models like the A4 and Q5 and the quattro system unavailable on petrol models. The 3.0 V6 diesel's have gone from the A4 and Q5 ranges altogether. It feels like an interim range at the moment and cant be doing sales any good. Other manufacturers like BMW and Mercedes don't seem to have this restriction with, for instance, their C43 and C63 models. Is this to do with new emissions laws and VAG group being caught on the hop?