There is absolutely a guarantee that all accounts that are not senior debt will be guaranteed to $250,000 aud. That is about as much of a guarantee as is possible to have, it is backed by the full weight of the Australian GDP, economy and financial reserves of the country.
I see no better guarantee on this planet other than death and taxes.
Certainly far better than a guarantee by the owners of a distributed data base.
As far as the cecaust rantings go, well they are just that, rantings and not at all any type of policy government or otherwise.