So this might have been the case however:

• Australia maintains a strategic stockpile for events like this.
• There was at one point no evidence masks stopped spread (after all, we didn’t know how it spread). Some people touted this as evidence masks don’t stop spread. This is a perversion of how evidence works and a very silly thing to think.
• You cannot change messages and expect people to keep trusting you. you need to be honest.

Australia’s readiness had been criticised for years, indeed it used to be one of the ways I bored everyone stupid at house parties when I got political. If the stockpile of masks was insufficient this was massively forseeable, although I think it was actually adequate and the pollies were just reckless idiots for panic reasons.