Insiders in the fast ring are today receiving a rather interesting update which goes by the name of "April 2017 update for Windows 10 Version 15063.138 for arm-based Phone Devices", rather than the usual naming scheme for Insiders.
The update is just build 15063.138 for Insiders in the Fast ring, which is the latest cumulative update for Mobile. What's more curious is the name in which Microsoft appears to have given it. Never before has Microsoft referred to Windows 10 Mobile as a version of Windows 10 for arm-based Phone Devices.
For those curious ARM is the architecture of the processor that Qualcomm uses (as well as Apple, and others) in your phone. It differs from x86 architecture for your PC.
Does this mean that there are versions of Windows 10 out there for x86-based phones too? Could this be Microsoft's new naming scheme for Windows phone-based devices? Who knows. At this point, Microsoft hasn't explained the reason for the name change.
It's also worth noting that for those not in the Insider Program, build 14393.1066 is now rolling out as well.
Perhaps it's just a mistake, but that would be a pretty odd mistake to make. Regardless, what do you think? Are you receiving the update on the Fast ring on your Windows 10 Mobile handsets?