physical currency is defined as "circulates as, and is customarily used and accepted as, a medium of exchange in the country of issue" so legal tender bullion coins would not be caught.
The definition you quoted is not stated anywhere in proposed Currency (Restrictions on the Use of Cash) Act 2019. The Anti-Money Laundering and Counter-Terrorism Financing Act 2006 is only referenced with regard to digital currency.
The proposed cash ban act clearly states "cash or cash-like products". It also refers to the Australian constitution "is or includes an amount of cash that is currency, coinage or legal tender for the purposes of section 51(xii) of the Constitution; "
This Act places restrictions on the use of cash or cash-like products within the Australian economy. The Act imposes criminal offences if an entity makes or accepts cash payments in circumstances that breach the restrictions. The Act also sets out rules for what happens when an entity that is not a legal person commits the offences.
9 Value of cash—foreign currency and digital currency
For the purposes of this Act, the value in Australian currency of an amount of cash paid in foreign currency or digital currency is to be worked out in accordance with the method prescribed by the rules.
COMMONWEALTH OF AUSTRALIA CONSTITUTION ACT - SECT 51
Legislative powers of the Parliament [see Notes 10 and 11]
(xii) currency, coinage, and legal tender;