It would be a shame to lose the wealth of knowledge with easy-ish search that subreddits like datahoarder provide if the subreddit is taken down or stays locked forever. Sure it is currently accessible, but will it stay that way?
I know it is being archived, but the accessibility part is the problem.
I’m not sure if it’s possible to retrodate posts, not even if it’s your own instance. But otherwise i think this might be the way.