If Musk woke up one day and decided to turn X into a Nostr based system:

 - Issued keys to every user account and allowed users to collect their keys or bring their own
 - Signed every message retroactively
 - Turned their internal servers into relays so users could collect the now nostr-compliant notes, or post them without being logged in; also for non-X clients to read notes from X relays
 - Enabled zap support

But X still:

 - Required you to have a user account for the npub notes to be accepted by their relays
 - Refused to accept and relay notes that violated their terms and services ie. moderated their relays
 - Terminated user accounts if/when a user violated their rules enough times
 - Maintained premium subscription tiers that restricted the types of data their relays would handle

What would you think about X, and Elon himself, if this were to be done? 

Personally I think it's not an ideal system, but it would be a massive improvement over the current. I also think it might actually be something he could be convinced to do.