I've read the legislation and watched a fair bit of the senate enquiry into it. We don't know yet what "reasonable steps" are to "assure" someone's age (because they get published in legislative rules that have not been authored yet), but they don't necessarily require linking with a RL identity. An example was given that it would likely be "reasonable" for Facebook to assume that the account holder is at least 16 if the account is more than 16 years old. So given mine is turning 17 in November I personally don't expect any Meta products to ask me to assure my age using any method that involves my government identity.

Additionally, affected social media platforms can't ask for government ID if that is the only age assurance method they offer. Some other methods include user interaction (does the user write posts like someone who is >16?) and facial age estimation (do they look >16 in their face pics?).

I'm just saying no need to panic and plan ahead for deletion just yet. If the legislative rules are "good" (as good as they can be in the circumstances) then you might not notice a different at all.