(Also see: Android N Features: What's New and Improved)
If a new string of HTML from the official Android Developer website is to be believed, select non-Nexus devices may soon be included in the Android Beta Program. A Reddit user in a post titled "Android Beta Program coming to OEM partners?" included an image showing the HTML code.
The HTML code of "What's New" section mentioned "More supported devices, including devices from OEM partners." The complete text said, "Accompanying Android Beta Program for consumers, starting later in the preview. More supported devices, including devices from OEM partners. Seamless OTAs for your devices, from initial release to final N release without flashing." We can expect Google to officially announce support for OEM partners in Beta program soon. It is unclear as of now how many OEM partners will be supported in the Android N Developer Preview, and of course, OEMs themselves probably have to develop the builds.
Last month, Google started rolling out its first Android N update for Nexus devices enrolled in the Android Beta Program. The first update addressed some performance issues.