Huh, I’ve not heard of this, though it doesn’t surprise me.
In the area where I grew up (waaay out in the sticks, with no easy public transport access to the closest AEC office), the AEC tended to send people out to your home on your 18th birthday (or soon after it) and enrol you on the spot. This was decades ago, though, before you could do any of it online.
As a fellow Australian - where the heck did you find this unicorn of a location?! I’ve been house-hunting (well, land-hunting, really) for over a year, and everything seems to come saddled with a bushfire overlay, flood overlay, or both. I’ve pretty much resigned myself to being stuck in a bushfire zone.
(Note: not asking for you to dox yourself with the actual location, though I am deeply curious.)