They don't have to lobby anyone for this. Apple has operations in aus. We have laws here gov can force you to put a backdoor in software or hardware and you are not allowed to tell even your employer you have been requested to do so.
Tbh in theory apple aren't allowed to tell you they have done it or otherwise. So their phones have probably been backdoored for a few years now at request of aus gov.
I would not be surprised if there is a backdoor already. Either explicitly ordered or secretly inserted like Dual_EC_DRBG. They’re not burning a zero day vulnerability or certificate authority just to convict one defendant. They’re saving them for something like Stuxnet.
Tbh in theory apple aren't allowed to tell you they have done it or otherwise. So their phones have probably been backdoored for a few years now at request of aus gov.