What it means
Meeting chat access depends on meeting type, attendee role, invitation and organizer settings. A recurring meeting can carry chat forward across sessions, while channel members can see channel-meeting discussion without attending. A file pasted into that chat can have separate OneDrive or SharePoint permissions. Restricting chat to the meeting does not automatically revoke a file link sent during it.
A real-world example
An external speaker joins the last ten minutes and receives a document link in chat. After the call they cannot read the chat, but a broadly scoped file link still opens from their browser history.
What to do
Set chat lifetime in Meeting options, inspect who can see the conversation, and audit each shared file's Manage access panel. Share approved follow-up directly with the intended people.
The distinction that matters
A meeting lobby decides who enters a call, not who retains a chat transcript or can open a recording. External and anonymous attendees may have different after-meeting chat access from invited internal attendees. A forwarded meeting invitation may also affect access. Treat the chat setting, file link and saved artifacts as three separate controls, and test each where the information is sensitive. For a channel meeting, inspect channel membership as well as the calendar invitation.
Microsoft meeting chat Microsoft meeting options
