The Nvidia Web driver for 10.12.1 (16B2555) is finally out. I was at 10.12.1 Beta 4 (16B2338c) and I had to upgrade it to 10.12.1. In my case it's takes perseverance and click open Apple AppStore upgrade.
There were two simultaneous upgrades showing up under upgrade in my case (10.12.1 & 10.12.1 Beta 5). I found out by clicking more under 10.12.1 Beta 5 update. I saw 10.12.1 update under 10.12.1 Beta 5 update, I selected 10.12.1 because there is no way in hell I will touch that 10.12.1 Beta 5. It took me 3 times to get it right. After successfully updated from 10.12.1 Beta 4 (16B2338c) to 10.12.1 (16B2555), Nvidia web driver update manager popped out and say driver update available. I click install, restart and everything back to normal. Dual monitors with correct resolution scaling.