Q. Can I in-place upgrade to RS3?
A. An in-place upgrade from Windows Server 2016 to RS3 is not officially supported however in my limited tests it did work for a few lab instances. Note that this is only for Server Core to Server Core. This is because:
- There is no upgrade for Nano (ever, you just redeploy the container built on the new image)
- There is no RS3 of Server with Desktop Experience as Server with Desktop Experience is Long Term Servicing Channel only.