I am looking for some support documentation related to NIC Teaming and Active Directory Domain Controllers. In the old days pre 2012 I know this was a hard NO. Is this still the case? If NIC teaming is supported, what is the preferred Teaming mode?
As far as I know still not recommended for domain controllers. If a domain controller is approaching the limit of a single NIC then that's a pretty good indication of general overload and the need for additional domain controllers.
As to supportability; when an issue arises and call is made, you'll likely need to disable the team as first step in the debugging process.