As a Microsoft Enterprise Agreement customer, do I need to report my license consumption only at the true-up anniversary date?
In the Enterprise Enrollment (EE), Microsoft differentiates between Enterprise and Additional Products. The need for Enterprise Products needs to be reported at the true-up anniversary date.
The need for Additional Products, however, which have not been licensed under the Enterprise Agreement yet, needs to be tracked over the year. The maximum need of licenses during the term must be reported to Microsoft.
The Server and Cloud Enrollment (SCE) does not differentiate between Enterprise and Additional Products. Therefore, the maximum need of licenses during the term must be reported to Microsoft.

Source: True-up Guide_Microsoft_as is 2017-08-03