I would think that this is an effect of our recent change of elevation service rather than the cache being archived. It turns out that a number of caches were previously reported with old elevation values (where a mine was being refilled) while the new service has updated values. As always, the information that is used for statistics for a cache is the current value regardless of what the value was when you logged the cache. This usually mostly applies to D/T and cache size which tends to change now and then, but occasionally elevation can also change even without the cache itself actually being moved.