One flaw you maybe missing in this is that any Bank/Credit Union requires an upstream bank to provide clearing/settlement. Only the main banks can provide that and if they refuse to provide you settlement services due to associations with bitcoin then your bank/credit union is rendered useless.
Sometimes yes you do need an Up stream Bank.
However the RBA/APRA/ASIC etc are unlikely to allow upstream banks to refuse services if they grant an ADI.
The Australian Govt and Legislation is committed to competition including financial competition. Banging deregulation has be happening since the 1960's or around then in various stages. Banks can not behave in an anti competitive manner. Denial of service to a licensed ADI would be anti competitive.