You're wrong here. It can't be due to strong content as it was shown after 8:30pm/9pm which means the family part of the evening is over so they can show more adult content.
Australian TV does this with a lot of concerts here. It's just our advertising breaks, no other reasoning behind it.
EDIT: In the advert for it, there's the shot of M humping the floor in Like A Virgin, so it definitely isn't due to strong content.
Sidenote: They also advertised it purely as 'Live in Sydney' though, which is funny because there's barely any footage from the two Sydney shows from what I've seen.