I plan to use Virtual Machines in NUC6i7KYK, using Hyper-V and Docker, and it seems Windows Server 2016 supports Docker better, from what I understand. And maybe VM's in general in Server have more performance and more features with Server 2016.
Is it safe to use Windows Server 2016 or should I stick with Windows 10?
In regards to your question, on the following link you will find the operating systems that are fully compatible with the NUC:
Windows® Server 2016 is not showing on that list, that means the NUC was not tested with that OS, so we cannot guarantee that it will work, you can still try to install it but in that case there might be a problem in regards to drivers because they will not be available for that OS, it is fully compatible with Windows® Server 2012 R2 though.
Any questions, please let me know.