There’s an updated (2017) licensing datasheet for Windows Server 2016. The layout is reworked and information on Storage Server, MultiPoint Server and Hyper-V Server is removed. Find this datasheet in the Core Infrastructure section in http://bit.ly/MSLicensingGuides.
Microsoft announce Premium Assurance on 8 December 2016 (http://bit.ly/2hxi0ix) which is a way of adding six more years of product support for either Windows Server or SQL Server.
There’s a useful datasheet which gives more details, but here are the highlights: you need SA to be able to purchase Premium Assurance, and you must purchase it for ALL servers with active SA in an EA, EES or SCE. You also need to acquire Premium Assurance for a product before it goes out of support, and the price will go up over the next few years – from March 2017 it will be 5% of the licence cost rising to 12% from July 2019.
You can find the datasheet in the Core Infrastructure section in our Licensing Guides emporium: http://bit.ly/MSLicensingGuides.