The latest documentation on nested groups has not changed. This document is dated May, 2018, and applies to both Windows Server 2012 and 2016 (and 2019):
https://learn.microsoft.com/en-us/windows/win32/ad/nesting-in-native-mode
This document on new features in Windows Server 2016 makes no mention of changes to group nesting:
https://learn.microsoft.com/en-us/windows-server/get-started/whats-new-in-windows-server-2016