https://redmondmag.com/articles/2019/10/28/office-365-groups-automatic-renewals.aspx

Microsoft on Monday announced new modified group expiration controls for Office 365, allowing groups to automatically renew if there’s been user activity.  The new policy, now at “general availability,” slightly alters the current Office 365 groups expiration policy that was established last year within the Azure Active Directory Admin Center portal.