Exchange Server 2016 Cumulative Update 1 does include updates to Active Directory Schema. These updates will apply automatically during setup if the permissions and AD requirements are met during installation. If the Exchange Administrator lacks permissions to update Active Directory Schema, a Schema Admin should execute SETUP /PrepareSchema before installing Cumulative Update 1 on your first server. The Exchange Administrator should also execute SETUP /PrepareAD to ensure RBAC roles are updated correctly.
Exchange Server 2013 Cumulative Update 12 does not include updates to Active Directory, but may add additional RBAC definitions to your existing configuration. PrepareAD should be executed prior to upgrading any servers to CU12