This can be a slippery slope. What is to stop any group of people, indoors and unmasked, from saying they were having a "religious service?" OK, a Mass in a Catholic Church is pretty obvious, but other religious services might not be. Any group participating in a rally, a party, whatever, could say the police outrageously interrupted their "religious service!"
Having said that, I do think having the police burst in on perfectly legal gatherings is WAY over the top. It conveys a police state mentality. Especially with that many people vaccinated in Australia, what are they so afraid of any more? Even if the Catholic service turns out to be a spreader event, it probably isn't any worse than the usual "there's a lot of it going around" kind of bug that spreads all the time. I think that's what Covid will settle down into, IF most people are fully vaccinated, preferably with boosters. The police should not be involved at all.