We need a #NOSTR #NIP that enables a client to download our entire event history from one relay, and upload it to another relay. This way if you are concerned that you will be deplatformed, you can easily migrate your chat history to a new relay. Or perhaps you setup a new private relay and want to upload your entire event history to it so you have a backup. Currently, as I understand it, a client cannot relay our past events from one relay to another.
Discussion
What are the reasons for being deplatformed?
Who knows? Perhaps it is simply that a particular relay is shutting down and you are concerned about losing access to your message history.
Personally, it is all about having my own backup of my entire Nostr history, on my own private relay. Currently if you didn't post a message to the relay originally there is no way to add it to the backup relay later.