Read this article.. Android 7.0 and the Snapdragon 800 — a conundrum
http://www.androidcentral.com/Android-7-snapdragon-800
In it, Jerry (the man, the legend) posits that all Snapdragon 800 and 801 devices will not be able to officially upgrade to Nougat. It has to do with support for the OpenGL ES 3.1 libraries. Apparently Qualcomm did not implement support for the OpenGL 3.1 libraries in flagship SoC's until the Snapdragon 805. The GPU, Adreno 330, is shared by the 800 and 801 chipsets, per Qualcomm's website:
https://www.qualcomm.com/products/snapdragon/processors/800
What I'm saying is that because of this, our less than 1 year old phones are not going to get major OS updates. That's exactly why I rooted my XPE in June and I am sooo happy I did! The folks at XDA are miracle workers!