if you pick your own relays you already know their stance on deletions, no?
Discussion
its not just relays, clients can cache notes and ignore deleted. damus ios and notedeck work this way atm. there will be thousands of clients that won’t support deletes
Also your notes could get propagated to relays beyond just the initial set you post to. Relays sync between each other all the time
deleted, signed events can be rebroadcasted to any relays that will accept them