A quick post:
We have found that our users that have updated themselves to Windows 10 have effectively locked themselves out of the network, from remote locations. It seems Windows 10 is not supported by our Citrix Netscaler VPNs. Of course we put a note out to our worldwide users, but some "had" to update. Hopefully there will be a patch or fix soon.
At the moment, we don't support Windows 10 in the infrastructure. That doesn't stop some of our users from updating anyway.