As I explained in the answer to which the Deputy refers, under EU legislation, Ireland issues licences only to people whose 'normal residence' is in Ireland. 'Normal residence' is defined in EU law in the first instance by a person residing for more than 185 days of the year in a given EU Member State. I explained in that answer the exceptions to the 185-day rule.
If an Irish citizen is residing indefinitely in another country they do not meet the residency requirements and are not eligible to replace or renew their Irish licence.
As Ireland has an exchange agreement for driving licences with Australia, if the licence of an Irish citizen is lost or stolen the person can request a Letter of Entitlement/Driver Statement from the National Driver Licensing Service (from info@ndls.ie) at a cost of €15. A letter of entitlement or driver statement refers to a copy of a driver record with details of name, address, date of birth, driver number, date of expiry of licence and class of licence to include details of what that class refers to. This can be presented to the Australian authorities as part of the application for a driver licence exchange.