We don't know yet how long this will continue.
However given that with international flights that open for check in three hours prior. many passengers arrive prior to that to get a space in the queue (since amazingly lots do not pre check in via Internet), one can expect many domestic passengers to take airlines and airports at their word and arrive a bit ahead of two hours prior to official departure time.
When will airport facilities (kerbisde entrances to airport buildings landside, VA and QF lounges, airport shops, security scanning to domestic airside and so on) begin opening even earlier to cope?
For instance, QF normally has a Monday morning (Tuesday if a public holiday) 0530 hours flight from MEL to SYD. On that morning, will the Qantas Club and Chairmans Lounge begin opening at 0330 if they do not at present?
Will public transport such as the Sydney and Brisbane airport trains (private contracts at the stations for the first, and stations and operations for the second) or SkyBus in Melbourne have to commence earlier, or roster more trains and buses to cope at an earlier departure time from CBD railway stations or bus terminals?
I'm assuming with all this there is a lag effect and also a 'hey boys and girls, we'd better check with the government/ airport/ tenants/ security to see if this is the new reality, or just a passing fad that will see a return to previous practice in two weeks.'