Rikafip pointed you to the right source. If a post gets deleted or edited you could always find an archived version of it as long as it has been scraped.

For example, I would think at quickest a cron job would run every minute which means if a post was made and deleted after a scrape already took place but before the next scrape was due (within 59 seconds), it will not be archived.

If cron jobs are not being used and some other method is being used for crawling then it would depend on the custom coding but I would highly doubt if in this scenario anything other than cron jobs are being used to scrape.