It might be shocking news, but None of OEMs gonna provide Android N update if Ur phone uses Qualcomm SoC having Adreno 3xx series GPU. As Adreno 3xx series GPU don't support Vulkan amd To provide OTA and pass Google Compatibility Test Suite Android N should have Vulkan support. Unless Google pass it, u will not get, but U can expect Unofficial port without Vulkan API.
It will affect Moto E2nd (LTE) and G3(LTE) as well as G Play(LTE).
Nobody can predict about new upcoming Moto Device will support or not like Moto E3 most rumored. Except these devices all fall in safe place of getting N updates.
It will affect all OEMs devices.
Amd Mediatek SoC uses Mali and Exynos PowerVr and those mostly announced and launched in 2015 and up SoCs might support It if they also support Vulkan, otherwise they will also not get.
Vulkan is must API need to be embedded in Phone if it runs Android 7.0+.
U can download Android N compatibility Document from developers.android.com