As the show is in Australia, it has already occurred. Main show began at 3AM EST this morning.
As for the broadcast everyone else gets to see: despite the fancy name, this is the regularly scheduled episode of Collision which airs tonight (it's just special as its in Australia, and extra star packed as a result, and with the filming of an ROH special paired with it which I presume airs next week), as such for anyone who wasn't watching live this morning: there is no preshow, and should air at the regular time Collision normally does in your time zone unless they state otherwise. The AEW website also says "Immediately following NBA All Star Saturday Night" on all its match placards so I assume if the game runs long it might be delayed but should air right after.
See shit like this is why I changed the last line of the discussion threads to 'Please check your local listings for more information on how to watch' a year ago goddamnit lmao