There's a working group for doing this but it'll be a while before anything is adopted at scale.
If fully public is okay for you, there is actually already a chatroom/IRC-esque platform called Roomy. It works well but it is all public and there's a touch more latency than a normal client-server platform due to the nature of atproto's gossip protocol.
They are working on this, but it's still gonna take a while as I understand.
It's also generally not advisable to make your cypher text publicly visible
That being said, I'm working with others in the ecosystem on "permissioned space", which are much closer to how people think about Google Docs and similar systems working.
There is also another effort around E2EE content (MLS) for messaging. They are also thinking beyond just messages too
