Lol the idea of a cover-up is laughable.
Workplace investigations are subject to a pretty decent level of confidentiality. You can't even discuss them with colleagues, or you're done for serious misconduct. And if there was an AHRC lodgement, you can ramp that way up.
If there was a settlement at the AHRC then the basic terms include confidentiality AND non-disparagement agreements at least. I'm sure you can imagine what else lawyers would put in the terms for a high profile matter...if it's part of any proceedings in the courts relating to alleged thefts then I imagine that plays a part too.
Even taking all that out, what does anyone seriously expect CA to do? The investigation concluded there was no wrongdoing.
"Hey...so we've called this press conference to let you know Tim Paine has been sending raunchy texts to some chick. What? No it was consensual. Hmm? No, sorry, there's been no wrongdoing. Yes, that's right, were basically here discussing a Test players sex life. Check out this picture of his penis he sent her! Ok, thanks for your time."