Microsoft crushes hopes of current Windows Phone users — no full Windows 10 coming to existing handsets
In December of 2016, Microsoft announced a partnership with Qualcomm to bring the full Windows 10 experience to devices running on Snapdragon SoCs and potentially other ARM chips. Ever since this announcement, Windows phone owners held onto the possibility that their current phones would be able to support the full Windows 10 on ARM experience. They had good reason to, as well, as Microsoft has a well-earned reputation for ditching support for products before they've reached anywhere near their life-cycle's conclusion (and Windows 10 mobile was still so polished at the time). These poor Windows phone owners can give up hope now, as Microsoft exec Joe Belfiore has confirmed that no existing Windows phones — Lumia 950 and 950 XL included — will be getting Windows 10 on ARM.
Interestingly, Belfiore's explanation also puts doubt as to whether we would see any phones running Windows 10 on ARM in the future at all.
"The Windows 10 on ARM effort is about enabling the PC experience on devices that are built on ARM so that they're connected all the time and have great battery life. So the experience is a desktop PC experience, it's not a phone-like experience. For phone-like experiences on ARM, we have Windows 10 Mobile. What Windows 10 on ARM is, is a desktop-like experience so that you get the battery life that ARM processors tend to have."
In other words, a "Surface Phone" running Windows 10 on ARM is not their intended goal. Instead, Microsoft is aiming Windows 10 on ARM at notebooks and tablets, leaving Windows 10 Mobile for the phone form-factor. That doesn't mean nothing like that can happen in the near future (or from another OEM), though; it just isn't Microsoft's focus.