It's not URC saying it won't run. MS is saying that there may be an issue with it. No doubt MS is saying that because, as usual, URC refuses to do any development work in advance of any OS release. Blame URC for a lousy approach to this issue, like they have had every time MS has released a new OS.

I have tried CCP on Windows 8 Pro. There is no problem running CCP. There is a problem, however, with Mobile Device Center. It loses connection with the remote and does not stay connected long enough for upload/download. I have not yet figured out a fix. Until someone figures it out, I would not use a Windows 8 based PC to program a URC remote.