If you're adding an external user from a new organization/workspace, they will see an empty universal channel when they're added.
If you're adding a user from an organization or workspace where the universal channel has already been created, they will see the message history when they're added.
Message retention settings follow the rules of each user's respective organizations.
For example, Joe and Jennifer from Mio are chatting in a universal channel. If they invite Tom, a consultant from Acme, he will see the universal channel welcome message but no chat history. Only Joe and Jennifer can see messages from before Tom was added.
However, if they add Terry, another consultant from Acme, Terry will be able to see the message history, but only as far back as when Tom was first added.
Chat with contacts on Slack, Microsoft Teams, and Webex Teams by installing the Mio Universal Channels app in minutes.