This is mainly a defense against large data leaks like the discord one, if we want stronger protections against cloud spying then we would want something like at rest encryption for nostr notes, which is an implementation detail 

 The Discord one was not a data leak

It was people complaining about how their groups got scraped when they had the join link public.

Same thing can happen to Nostr 

 Groups should be encrypted either way except if they are public. 

 Groups should be encrypted either way except if they are public.