Teams live events (https://docs.microsoft.com/en-us/microsoftteams/teams-live-events/what-are-teams-live-events https://docs.microsoft.com/en-us/microsoftteams/

Teams live events (https://docs.microsoft.com/en-us/microsoftteams/teams-live-events/what-are-teams-live-events https://docs.microsoft.com/en-us/microsoftteams/teams-live-e...) which the parent comment was refering to is actually a specific feature in Teams that is only available for certain levels AFAIK but supports vastly more people than a standard Teams meeting.