when a message is deleted, it should...
immediately disappear for everyone and be permanently missing from history (Discord behavior)
11.1%
be immediately replaced with a "deleted message" marker, which remains in the history (Matrix behavior)
55.6%
be immediately replaced with a "deleted message" marker, but disappear from history
27.8%
something else
5.6%
Poll ended at .

@exa Behavior 2 by default, but allow zone administrators to remove the marker. That way it preserves some context by default, but doesn't prevent fully expunging an auto-detected spammer, for example.

(Either way, ideally best-effort clear notifications for subsequently deleted messages)