That shouldn't be a problem as long as the posts are scraped and archived even before the deletion. However, what if a post is deleted within 5 minutes after it has been posted in a self-moderated thread?
That's not a problem. My bot scrapes all posts within seconds after they are posted.
Post created -> post scrapes
Post deleted after 1 min ...
Post rescraped after 5 minutes, bot notices it's missing = mark as deleted