Good question! Long form content uses a different kind that kind 1 notes. These long forms events are editable, unlike notes, so you can go back and fix your typos! 😊 In general the last version is stored on nostr, although some relays may store all versions.
Wait... how come I was able to edit my long-form post in https://hable.news nostr:npub107jk7htfv243u0x5ynn43scq9wrxtaasmrwwa8lfu2ydwag6cx2quqncxg , even though I can't edit normal notes on Nostr?
(Took the opportunity to edit my latest post to include a section about wishing to have the ability to edit notes and mention how it can be potentially done)