Glen
You might want to contact the Committee Secretary to confirm (Phone: +61 2 6277 3511 or
[email protected]), but I'm pretty sure that anything published before submission to the Committee (e.g. an AOPA webcast or even a transcript of it) will not attract parliamentary privilege. Although that would not mean you can't participate in an AOPA webcast, it would mean that any e.g. potentially defamatory content of the webcast would be at your/AOPA's risk.
If you instead write down what you have to say about the CASA officers you've named and submit that to the Committee and the Committee publishes your submission
before any proposed webcast, the content will attract privilege and be 'out there'. But beware: You're starting a verbal streetfight with some of the best sophists in the game.