I upgraded to 9.10.2 MR overnight, and all appears to be well. Windows 10 provisioning works now. That's rather a big relief.
I'm not sure if this is a 9.10.2 thing or if it worked like this before, but the provisioning process is a lot cleaner/intuitive for non-tech people. When I connected to the provisioning SSID, it took me IMMEDIATELY to the signin page for the download (users used to need to try to get to a www website before being redirected to the signin page). Then, when I signed in, the download started immediately (users used to have to click to download). Then, when I ran the installer, it connected my laptop immediately to the appropriate SSID (previously, at least some users had to connect to that SSID manually). Small touches, but nice.
I'm curious of I simply missed these small improvements before, or if it's because of the provisioning being more intuitive because Windows 10 works better with it.