Article misses an important point: what is the latest date it definitely wasn't there? There's nothing in the article that makes it more recent than 1928.
Australia’s a pretty big place and what population it has is mostly clustered in a few coastal locations. There are tons of spots that haven’t been visited in thousands of years, and possibly ever, despite 60Ky of inhabitation.
Visitors find it hard to grasp. Imagine if half the population of California inhabited the “lower 48” states. Where would they live?
It is light on details such as how it was made (mechanics). But erosion has meant its needed to be redefined.