http://thetrademarkninja.com/2016/10/03 ... rademarks/
The part in there (but today it may have changed)
Is PIXEL was given to Google for the operating system class9. It runs on the Pixel version of that current Android. That would be the blocker, not the 'phone or device name'.
And was unfortunate as it made life easy compared the convoluted Pi Desktop full name we should be using and I quite liked it.