From Microsoft Corporation
MC214522, Stay Informed, Published date: May 28, 2020
We are providing Teams meeting organizers greater control over their meetings by making it possible to require all participants to wait in the lobby.
This message is associated with Microsoft 365 Roadmap ID 64643.
When this will happen
We will roll-out this feature in early-June for worldwide tenants and GCC tenants will receive it at the end of June.How this will affect your organization
After scheduling a new meeting, the organizer will be able to configure meeting options so that only the organizer can bypass the lobby.
After changing the meeting option to Only me, the meeting organizer can manage who is allowed into the meeting.
What you need to do to prepare
You might consider updating your user documentation and training materials.