Win10 1709 no Bluetooth w/ 2016 13" MBP (Touch Bar)
2016 13" MacBook Pro (touchbar) running macOS 10.13.3, with a Boot Camp partition.
While at the office, I use an external display and Apple Bluetooth keyboard. When running Windows 10 1703 via Boot Camp, the Apple Bluetooth keyboard works normally.
If I upgrade to Windows 10 1709 ("Fall Creator's Update"), the Bluetooth keyboard will fail to function (although it is listed as connected in the Windows Devices control panel). Re-installing Boot Camp drivers does not resolve the issue. Restoring back to Win 10 1703 will restore bluetooth functionality (but is not a long-term fix). I've even gone so far as to clean install macOS and Win10, but the problem returns as soon as I update to Win 10 1709.
I also have a Late 2013 27" iMac running Win10 1709 via Boot Camp, which does not have this issue. However, I've seen multiple reports from iMac Pro users with the same issue (loss of bluetooth functionality with Win10 1709).
We saw an update to Boot Camp shortly after the 1703 release, but I've seen no update for 1709. I saw a forum post from Sept 2017 reporting a similar issue, but no resolution.