Bunjil: Unfortunately, the interest in maintaining this historic (2006) cache seems to have evaporated.
It can only be assumed there is no longer any interest by the CO in this placement and they have abandoned the cache - taking the next step and de-listing.
If there are components or remnants of the cache and you haven't already done so, please return to the GZ and collect the cache (or remnants). We don't want to litter our environment with Georubbish.