Thanks for the update on Australian citizenship laws.
It’s a bit odd, they have birthright citizenship but it does not kick in until the person is ten years old.
It reads as if the parents move (or are removed) from Australia before then, the children go with them and don’t become citizens, and the whole family isn’t kept because “b-but they’re parents of Australian citizen children!!”. It seems like it would cut out most of the anchor babies and birth tourism without being unfair to children who actually do grow up there.
I suspect it’s to prevent creating a citzen by birth when there’s no intention of living and contributing to the country.