Residency in another country after leaving Australia is not relevant for lodging early. See below for lodging early eligibility.
Lodge your tax return before leaving Australia | Australian Taxation Office
Whether you have to pay tax on income after departure depends on whether you have any Australian-sourced income after this date. (see above link).
If lodging early, advisable to prepare and lodge tax return before departing as this has to be done by paper and posted to the ATO.