Microsoft Teams meetings can be locked to limit participants. When a meeting is locked, invitees will still be able to access the meeting chat, recording and other meeting info, but no one else will be able to join.
To Lock a Meeting
1. Start the meeting
2. Click on People at the top of the window
3. Click on the three dots next to Participants
4. Select Lock the meeting
5. In the window that opens, click on Lock
The meeting is now locked and no one else will be able to join.