@sime3000 - We are not publishing steps to block this. The .Net team has informed us that .Net 4.6.2 will not be offered as a mandatory package through Microsoft Update until after the end of the year at the earliest. The Exchange team has already been validating to ensure we have compatibility before this package is forced onto Exchange servers. Customers wishing to run on Windows Server 2016 already require .Net 4.6.2.
Customers who are concerned about this transition always have the option to configure Windows Update to review updates before they are installed. We will still have a hard requirement for this for all Exchange 2013 and 2016 servers with our March '17 releases.