Rev. Onan Canobite, SubGenius on Nostr: Part of usenet culture was that most people expected most of their posts to expire. ...

Part of usenet culture was that most people expected most of their posts to expire. It was known a private copy of a post could be made, but usenet itself deleted messages after a time as a storage-budgeting function. To re-post another person's post after it had expired was not always viewed with favor. There was no expectation that archives would or should be saved, nor that they would be largely available again as happened later.

My lesson learned: assume nothing expires.