Australia as a whole moves northward? That wouldn't alter local relationships. The concern would be when land moves on a fault and plots become distorted, like those well known pictures of roads and streams jogging sideways on the San Andreas fault.
The point is that if our properties are defined using survey markers (like my deed, which literally spells out in English where the plot starts, how many feet this way and that) this will stand up to ground shifting. It will be the mapmakers' problem to redraw the maps though.
It doesn’t stand up to shifting, often, because one landmark at one corner may move relative to another. If the fault is through the middle of the property.
