This idea is not as silly as it sounds. Anyone remember when Jetstar was starting up? GD suggested the use of an airport other than YSSY and was laughed at. It appears that a success has been made of YMAV so why can't the same be repeated at YSBK? It's also worth noting that YSBK is closer to the centre of the huge socio-economic group that would use LCC's such as Jetstar. YSBK is now in private ownership and would jump at the opportunity to establish a legitimate RPT operation. The local civic leaders would also probably welcome the influx of jobs that such an initiative would bring. The days of "one city, one airport" have long gone. Sydney is no different.
Although Airbus are in the business of "selling" aeroplanes, it's in their interest to push the envelop to identify and open up new opportunities for existing or new customers. This is just what they are doing. It will be only a matter of time before the baby faced assassin announces an order for a small fleet of baby Airbuses, especially as his drivers on the 320 can move straight into them, CASA permitting.