Thanks for the info! Seeing how we'll know 8 days before the GF, I'll probably do it 7 days before in anticipation of getting tickets to the game.you need to complete a queensland border declaration here qld.gov.au/border-pass/general
as long as you're only transiting through sydney and don't leave the airport you'll be fine under the current restrictions.. it appears you can make this application up to 7 days before travel.. should it be required i'd suggest making application as early as possible to get that approval confirmed..
we've booked refundable tickets transiting through sydney to the gold coast on friday 23rd..