The Exchange 2016 high availability solution is integrated with the Windows shutdown process. If an administrator or application initiates a shutdown of a Windows server in a DAG that has a mounted database that's replicated to one or more DAG members, the system will try to activate another copy of the mounted databases prior to allowing the shutdown process to complete. However, this new behavior doesn't guarantee that all of the databases on the server being shut down will experience a lossless activation. As a result, it's a best practice to perform a server switchover prior to shutting down a server that's a member of a DAG.
Как говорится, это настолько фейл, что даже вин!