While there's been speculation the Pixel Laptop would run Chrome OS, Android could be a much more likely platform.
Five years ago, you could easily pick up a Google laptop. The Pixelbook Go had just launched, and even the original Pixelbook was still holding its own. But in the years since, it's felt like Google's interest in the form factor has waned -- we never did get a proper Pixelbook 2, and the Pixel Tablet arrived without an official keyboard. While the Pixel Tablet 2 sounds like it could finally remedy that keyboard oversight, Google is reportedly also working on another return to this form factor, as we hear about development of a Pixel Laptop.