Thought this was interesting.
Looks like Google is seeking Windows certification for the Pixelbook. As others have speculated it is unlikely Google would ship with Windows 10 on their hardware but they could leave open a dual booting option similar to boot camp.
I have to think this is something being looked at for enterprise. Basically a “We think Chromebook will work for you BUT if you get it and need more or have that one department or project that wants it, toss Windows on it.”