They may or may not. If a chitload of people are going to ignore an Xmas lockdown (and I'm sure plenty would), it becomes a question of, "Is it worth even trying?"What are people's thoughts of, if or when Sdyney will be locked down. personally I reckon they will lockdown before XMAS to avoid the risks of family gatherings.
That's what they were trying to avoid in the UK, because I guarantee there will be plenty of people out and about on the 25th regardless.
Unless Boris takes a leaf out of the Chinese playbook and welds their doors shut .