You should read EULA every once in a while.

“We will access, disclose and preserve personal data, including your content (such as the content of your emails, other private communications or files in private folders), when we have a good faith belief that doing so is necessary to”, for example, “protect their customers” or “enforce the terms governing the use of the services”.

With Windows10 you already accepted that they will collect and share data. What is good faith to them remains to be seen but as a rule of hand I don't trust them for anything. In short, yes… Microsoft is seeing your information.