Does the place become less dangerous in some miraculous way?

Yes for citizens, it's a bit weird. Political refuges are different to war zones. Becoming a dual chinese/australian citizen and traveling back there on an Australian passport gives you some immunity because you are technically an Australian tourist. If anything happens then the Australian govt can get involved.

But if you are an Australian citizen and travel back there using your chinese passport, then the Australian govt can't do anything to help you. China wont recognise the dual citizenship.

The problem here is that a permanet resident is the step before becoming a citizen. They are people who probably would be citizens in a few years but aren't yet. So they travelled back to china using chinese passports. So the Australian govt is trying to help them but there isn't much they can do.

They were probably going back there to visit family.