Of course we are talking final versions here.I run an isolated win 10 version on a laptop and use a pure local account and turned off any and all information sharing. Am I sure my personal information is 100% secure? No but certainly am I sure there is built in key logger. And I am aware that nothing is 100% secure the second one plugs in an ethernet cable.
Definitely Win 10 preview version, final release version not so clear:
http://www.geek.com/microsoft/microsoft-clears-the-air-on-windows-10-keylogger-1606160/
Regardless of details Win 10 is a spyware but hey it can run some of your programs when it has spare time to do so and if it feels like running them.