No other smartphone that comes with this SoC has till now received a stable and official build of the new Nougat 7.0. (nashvillechatterclass.com)
While official builds are released by the manufacturer, the unofficial builds are usually leaks or test firmware versions. (android.gs)
Lead developers over the project have final say as to whether or not the code will be added to source and used in official builds. (androidheadlines.com)