Explain the problem as you see it
Tana seems to have all the elements needed to be a perfect productivity app for teams - except for linear thread-based communication.
Why is this a problem for you?
Needing to have a separate app for team-communication, when Tana does basically everything else, is annoying. Tana is so close to being the 'Everything OS' for teams!
Suggest a solution
Allow users to create threads similar to AI Chats, that allow other users to add 'messages'. Show the sender's avatar next to their message, and disallow editing from other users.
These are a type of node like AI Chat nodes, that can be referenced and tagged, but belong to specific users, and to a specific thread.
It would also be cool if you could start threads from messages within a thread, to get sort of a branching, exploratory thing happening.