Jack. No we havn't. The CASA NOTAM is WRONG!
The multicom is clearly the correct frequency for non marked runways based on the decision made on airspace policy by Federal Cabinet.
We will see how long it takes for the NOTAM to be corrected- probably quite a while. In the meantime remember if you comply you could be blocking out important ATC instructions to large air carriers - and this could result in an accident.
In this case do what safety dictates is the right thing. Sometimes the law is an ass.