I doubt that Apple will build a significant backdoor. Most likely they will figure out some symbolic way to accommodate this law, exploiting the vague wording.
The nuclear option is probably to just stop selling their products in Australia. The population of Australia is only 25 million people. It would be a huge hit but not insurmountable, and then the Australian politicians would face significant backlash and probably walk back the law.
The nuclear option is probably to just stop selling their products in Australia. The population of Australia is only 25 million people. It would be a huge hit but not insurmountable, and then the Australian politicians would face significant backlash and probably walk back the law.