Q. Will the new builds for Windows Server 2016 Nano Server Current Branch for Business be installed automatically?
A. No. While it is important to stay current as new Current Branch for Business (CBB) as only the most current and previous branch are supported there is no automatic upgrade. Instead you will upgrade as the new builds are released which will be a simple excercise, for example as an optional upgrade through Windows Update or on-premises solutions like WSUS. You will not be able to use Configuration Manager as this does not work with Nano Server currently.