Maybe timestamps could indicate versioning. Sounds like we need relays to treat them differently though.
Just came up with a new plan for fixing replaceable events with nostr:npub12262qa4uhw7u8gdwlgmntqtv7aye8vdcmvszkqwgs0zchel6mz7s6cgrkj
The biggest issue with replaceable events (contact lists, profiles, lists,) is that there is no versioning scheme. This leads to many issues where your contact list is dropped, comments+likes+zaps appearing only on older versions of a post, etc.
We need a concept of versioned events in nostr and a way of querying those effectively. Looking forward to working with nostr:npub12262qa4uhw7u8gdwlgmntqtv7aye8vdcmvszkqwgs0zchel6mz7s6cgrkj on this and implementing it in Damus, nostrdb and hopefully strfry once we figure it all out.
Discussion
We just need to not add information destruction as a core protocol feature. It leads to many awkward outcomes.