As per Executive Traveller (
https://www.executivetraveller.com/n...flights-banned), the Victorian government has requested from the Australian Federal government to divert all international flights from Melbourne for the next two weeks, due to the increasing number of Covid-19 cases in Melbourne. It appears likely that the Federal government will grant this request. For flights that were bound to Melbourne, passengers will need to quarantine for two weeks outside of Victoria before travelling there.
If anyone is planning on travelling to Australia, and specifically Melbourne, it would be wise to delay for at least a few weeks if you can. Because even if you get to Australia, it will be hard to get to Victoria right now because of reduced travel options within the country.