Yesterday, the Australian Bureau of Statistics (ABS) released Overseas Arrivals and Departures data for December, which confirmed that net migration into Australia has swung sharply negative.
Australia has lost nearly 19,000 net permanent & long-term arrivals since the pandemic hit in March 2020 – the first time net arrivals have been negative since the data series began in 1976:

Accordingly, annual net arrivals plummeted to only 96,700 in the 2020 calendar year, the lowest level since 1999:

As shown in the next chart, there is a strong correlation between the ABS’ monthly net permanent & long-term arrivals data and the official quarterly net overseas migration (NOM) data, which is only current to June 2020:

Officially, Australia recorded NOM of -5,900 in the June quarter as international borders were slammed shut:

Thus, based on the above monthly net arrivals figures, NOM should record negative figures over coming quarters.
This aligns with the October Federal Budget’s NOM forecast, which projected declines of -71,600 in 2020-21 and -21,600 in 2021-22:
Much will depend on the speed and effectiveness of the vaccine rollout across the globe.