With the recent edict by GC to encourage cachers to pick up old containers that have been left after a cache has been archived - having a league table of cachers finding caches after they have been archived only encourages those caches being left out - yet as they are not longer technically in the game it was felt this should not be so 'encouraged'.
Logs will not be deleted - you get the issue of challenge caches being found and then later qualified for and sometimes this occurs after the challenge cache has been archived so they can't get round that yet obviously in those circs there isnt the issue of containers being left out there