That will be very unfortunate. This could mean even Amanda, Grant, the judges and the crew will have to undergo self isolation as well.
EDIT: Amanda has gone into self-isolation after coming into contact with Christian Wilkins. That means she may not be able to host this Sunday’s show.
While it’s good news that Christian has been given the all clear, he and Lily won’t be able to perform on the same set as his competitors, as per 10Daily article:
Christian and Lily will appear on Dancing With The Stars remotely during this Sunday’s show, returning to the dance floor the following Sunday. As a precaution, all Dancing With The Stars cast and crew will continue to self-monitor for symptoms until the end of Christian’s self-isolation period.
So hopefully she’ll be able to host from the set on Sunday now that Christian has been given the all-clear?
Amanda was given the all clear yesterday (Thursday), so yes, she will be able to host from the set this Sunday.
UPDATE 22/3: The Sunday Telegraph reports Christian and Lily will perform their dance routine on a Melbourne hotel rooftop today with unmanned cinemas and minimal lighting. And rain is forecast for the city today.
Are TV shows going to be exempt from these lockdown laws? Do we have any of the remaining dancers or people who work on the show who have to fly in?
No. I would say they are going to have to stay in Melbourne until the show is finished.
they may have to fast track it as melb will be next to lockdown
Melbourne will close up the same time Sydney does.
I can’t see this show going past tonight.
That’s different. But there’s no other ways to go around it.
I would’ve thought they would do an emergency finale tonight and wrap up the season. Pretty optimistic that something so non-essential will be allowed to happen next week.
But what if dancing is your life!?
Then get a better life 
Last night’s show took a 15-minute break to take the Prime Minister’s press conference. I believe the show aired uninterrupted in Perth due to time difference.
At the end of the show, Amanda hinted DWTS might be affected by reasons beyond their control, but hoped the semi-final would be on air next Sunday night.
They should just cut their losses and pre-record next ep as the finale during the week. Give the contestants a few days to learn final dances . I think they could still do it during the week as it would be considered work, right?
Might be hard to do that if they need to practice their dances. I think they should just cut the loses and end the season.
That’s why I said later in the week. Give them two or three days to learn then film it and be done with it. I could be wrong but I don’t think the current restrictions necessarily have to mean it stops (i.e. if the number of people in the room are sufficient and it’s considered work) but they probably should try and think about wrapping it up ASAP.
Did Dami get booted last night? Or has the show been canned?
Yes.
They’re hoping to get a show next week but with everything that’s been happening it looks unlikely.