I don't know if the A380 would get into Avalon or not (anybody know?).
Qantas brought A380 VH-OQA into Avalon for a while last airshow. It was there on one day only from about 1000 until about 1500. I suspect it had real work to do before and after those times.
From another site
Please don't rely on a QF airplane being available for travel to Avalon, either as a staff member or as a member of the public via a Charity (ie Pathfinders).
Given the security requirements for passenger screening (which has to be done by hand thus a very long boarding time in the static display park) and the limited parking positions available to accommodate an A380 or B744 (thus necessarily blocking other display aircraft whilst boarding), it is likely to go empty based on issues over previous years.
These decisions are usually made very late depending on the commercial requirement close to the event and the ultimate availability of parking once all participants are confirmed.
I seem to recall a huge queue for boarding (took well over an hour to process) when they brought an A330 down in 2003. Haven't seen it done since.