Thats a good question to ask, especially if you have a long list of attendees.
Meet Now
Meet Now meetings expire 8 hours after the start time.
In other words, the meeting automatically closes 8 hours after you launched it.
For example, if you start the meeting at 10:00, it remains open until 18:00.
Can I Remove It?
On the other hand, regular meetings with end time expire 60 days after the end time.
While recurring meetings with end time expire 60 days starting from the last occurrence.
Microsoft Teams Events
Meetings that are several hour-long are usually live events or long-term planning events.
you might use Teams to host live events with up to 10,000 attendees with a four-hour duration.
you might read more about the limits of Microsoft Teams onMicrosofts Support page.