"blocking Microsoft Windows smartphones from "operating properly" with YouTube"
Couple of things to clear here. In the case of operating properly, Google kept trying to cut off the official WP app (made by Microsoft) just about any way possible. When the app was first out, Google complained that it avoided ads (like tons of other apps for YouTube) so Microsoft heeded the wish and disabled the app while they put the ads in. Put the ads in, relaunch the app, one day later Google revoked the API keys of Microsoft (as in all of them). You can still use IE to get to YouTube, but in that case the ads weren't available anyway!