As someone who operates about 300 sectors into YSSY each year, my memory of it is initially, when parallel operations started, a readback of the localiser frequency was required. However that did not last very long and ATC asked that it not be read back. I think that might have been done by a memo to operators from ASA before it was amended elsewhere.
In the last few years I cannot recall hearing anyone asked to readback the frequency.
I do have a question for ATC out there though. Non-jets are normally on a heading or turning to a heading when changing to director. The normal requirement is to state the heading when being vectored and changing frequency, but I notice on change to director a lot do not say the heading and director does not seem to care one way or the other. What is the ATC point of view of this?