When you create the Team's meeting link, it's going to be available for 60 days. If, after that time, no one uses it or updates it, the link will expire. If someone uses it on the 59th day, the expiration date will reset to another 60 days. So, you can schedule a meeting for the future and change the time if you need to; the link will remain active as long as you have the meeting in that time frame.