Ava, you're the security professional. How is it possible you believe a protocol change could retrospectively delete data in an open ecosystem with bad guys already within the walls?
Clipper chips and signed binaries? In an open protocol, no one can force anyone to "no longer participate in the network".
I know transactions can't be deleted from my node. I know torrents can't be taken down no matter how hard you try. I know if you delete a tweet, people screenshot and they find their way onto way back machine. It's a trade off we made for censorship resistance. If somehow we can control what other people store and serve in their own relays, we are also dead in the water. So then what? Open to your suggestions
"Greater privacy" is a moving goalpost. Not even XMR passes unrecorded and un-analysed. It is nearly certain that the first year's worth of transactions has been largely de-anonymised. XMR transactions are passing only a few bytes of unique information, and the set of participants is very large relative to the small uniqueness of the messages. This is wildly inapplicable to Nostr.