I almost struck out, until I ran into this: Outside of that fun, I dove into most of the tests looking for a slip-up that showed an odd-shaped device or a label that revealed the Surface Duo officially. We can see that the device supports LTE bands for all of the major US carriers, has Bluetooth, NFC, and 802.11ac WiFi.
The FCC docs for a Microsoft “phablet device” under model number 1930 are filled with your typical stuff. There’s no guarantee because Microsoft tried their best to hide all identifying info, but it sure looks like the Surface Duo stopped through for all of its testing and certification glory. I would tend to lean towards that happening if the device that just stopped through the FCC is what I think it is.
The Microsoft Surface Duo should be arriving here shortly, or maybe later this summer, if rumors are to be believed.