Is the minimum licensing requirement an Azure AD Basic subscription for every user within the groups that have licenses assigned, or is it just one single Azure AD Basic license for the tenant? The description in the article seems ambiguous to me, and a significant difference in cost...
A paid or trial subscription for Azure AD Basic or a paid or trial Office 365 Enterprise E3, Office 365 A3 and above editions is required in the tenant to use group-based license management. This feature requires license for each unique user that is a member of groups which are assigned license. You don't have to assign licenses to users for them to be members of groups which are assigned license, but you must have the minimum number of licenses in the tenant to cover all such users. For example, if you had a total of 1,000 unique users in all groups with licenses assigned in your tenant, you would need at least 1,000 licenses to meet the license requirement.
