On 2016/10/12 (yesterday), as Microsoft's TechNet article "Evaluation Versions and Upgrade Options for Windows Server 2012" suggested that it's relatively straight-forward to convert from evaluation to production, I downloaded the ISO for the evaluation version of Windows Server 2016 Standard from the Technet Evaluation Center, installed it, connected it to our Active Directory domain, and promoted it to be the second domain controller.
On 2016/10/13 (today), Windows Server 2016 was released (I knew I should have waited).
I logged into our Volume Licensing Service Center, obtained our SPLA product key and tried to activate which failed.
As advised by https://msfreaks.wordpress.com/2016/10/06/convert-windows-server-2016-evaluation-to-licensed/, I executed command
dism /online /set-edition:ServerStandard /productkey:WC2BQ-8NRM3-FDDYY-2BFGV-KHKQY /accepteula to convert from Windows Server 2016 Standard Evaluation to Windows Server 2016 Standard which completed successfully.
I executed command
dism /online /set-edition:ServerStandard /productkey:<our SPLA product key> /accepteula which failed and outputted the following:
Deployment Image Servicing and Management tool Version: 10.0.14393.0
Image Version: 10.0.14393.0
This Windows image cannot upgrade to the edition of Windows that was specified. The upgrade cannot proceed. Run the /Get-TargetEditions option to see what edition of Windows you can upgrade to.
The DISM log file can be found at C:\Windows\Logs\DISM\dism.log
I executed command
slmgr /ipk <our SPLA product key> which completed successfully.
Windows Activation is now reporting the following:
Edition Windows Server 2016 Standard
Activation Windows is not activated Product ID 00377-70126-37251-AA898
Product Key XXXXX-XXXXX-XXXXX-XXXXX-Y4HYC
We can’t activate Windows on this device because you don't have a valid digital licence or product key. Go to the Store to buy genuine Windows. Error code: 0xC004F012