Oddbean new post about login | logout True. I was thinking of when someone quoted or broadcasted notes. If that ought (or maybe already does) bring along a backup of the original note.
That puts the note on more relays.
That is not always the case. Many times clients just create a new note with an nostr:nevent1qqs... reference, meaning the quoted reply note can survive whatever its replying to. You see this in action when you see a note with a quote reply and it's content is: "This note is not available on any of your relays"