Just under a year ago, there were signs that Google was modifying the firmware of its Pixelbook laptop to enable dual booting into Windows 10. The firmware was updated to give the Pixelbook the ability to boot into an "Alternative OS" ("AltOS" mode).
The dual boot work was being done under the name Project Campfire. There appears to have been little development work on Project Campfire since last December. This suggests that Google actually decided not to bother with dual booting many months ago.
In some ways, Project Campfire highlighted just how strange Pixelbooks are. Pixelbooks are almost uniquely well-specced and well-built when compared to other Chromebooks, and they have the storage and computing power to comfortably run Windows. In general, other Chromebooks simply lack the storage space to possibly support running Windows alongside Chrome OS. As such, this wasn't a development that would do much for the wider Chrome OS community. Similarly, it's not really clear that Project Campfire would do a whole lot for Google, as the company is unlikely to have much interest in people buying a Pixelbook only to run a non-Google operating system.