Office 365 License Assignment
There is perpetually a lot of angst around licensing users for Office 365 workloads. Most of my customers over the years have wanted to ease into deployment, only enabling certain services at a time. Of course, as an evergreen service, we are always adding features, leading to new service plans to disable as you discover them.
Read more at source: https://blogs.technet.microsoft.com/undocumentedfeatures/2016/06/21/office-365-license-assignment/