ICAO is a division of the U.N. Both are toothless tigers.
There will be the usual morning meetings to decide to have afternoon meetings, licencing standards (the more complex the better, so we will get a big tick in the box there), a look at how records are maintained (not good, but a standard way to pass close scrutiny on an audit is give the auditors something relatively harmless to get their teeth into), training programs (some boring videos to watch), enforcement (we are good at prosecuting pissant cases, so they will like that), where CASA rules differ from ICAO recommendations (so what - the air is different down here), and lots of long lunches.
The worst ICAO can ever do is downgrade a country to confine its aviation activities to within borders, and Australia has a long way to descend to the level of a few places where that has happened (like Sierra Leone). CASA will baffle ICAO with bullsh!t.