Dalai, I'm right with you regarding the end of 2008. I still look favorably on 2008 R2 as a high point, but it's time in the sun is ending.
January 2020 cannot come soon enough for me.
Dealing with the mess of remediating tens of thousands of unsupported servers will be the next decades, Y2K moment.
They can also kill off the still born 2012 if they want. Hopefully these servers have all been in place migrated to 2012 R2.
That will also remove another significant workload on all the patch testers / deployers out there.
A small tweak on your statement below:
For 2008, the D3D patch is kb4019478. For 2008 R2 and 2012, it is as you said, KB4019990.