Microsoft doesn't have the best history when it comes to supporting ARM processors. Windows RT, the ARM version of Windows 8, can only be described as a disaster. And then there's Windows Phone and Windows 10 Mobile, which never supported anything other than a subset of Qualcomm's chipsets.
In fact, through the various iterations of Microsoft's mobile operating system, they always tended to only support last-generation Qualcomm chips. Windows Phone 8 only supported a few Snapdragon S4 SKUs, and Windows Phone 8.1 added the Snapdragon 200, 400, and 800, leaving a hole in the upper mid-range.
But Microsoft's next venture with ARM is going to be full Windows 10, using virtualization to run full Win32 apps on a Snapdragon 835. However, the Snapdragon 835 is almost a year old now, and with a refresh from Qualcomm coming up, you wouldn't be crazy top be skeptical about how soon Microsoft will support it.
According to a job listing first spotted by WinFuture, Microsoft is at least working on it. The listing calls for someone that "has done LTE Manufacturing test on QUALCOMM (8998, and SDM 845) and/or Intel Chip sets." MSM8998 is the codename for the current Snapdragon 835, and Qualcomm won't be using 'MSM' for codenames moving forward; instead, it will just be SDMxxx, so 'SDM 845' would be the next generation chip.
Of course, Intel experience is also necessary because Windows on ARM is part of the broader always-connected PC initiative. These can include ARM chips, but they can also run on Intel, as is the case with the new Surface Pro with Advanced LTE.
Qualcomm hasn't even announced the Snapdragon 845 chipset yet, and it's expected to do so at an event next week. Leaks have been scarce, so it's something that we know very little about right now.