Clearly there is a value proposition to having knowledge about all the bits in the phone, but as I discovered with the Android phones, working at Google, there are some bits which are protected in a variety of ways (basically most of the radios in phones these days are all software and that blob (the stuff that makes the radio 'work') is strictly licensed. It was, for me at least, an unexpected additional cost for the radio stuff. (I imagine that business model started with soft modems where the line access chips were $1 and the code to turn them into a 56Kbit modem was another $9 each).
Regardless of outcome, this will join a number of attempts at making a Linux phone. I wonder if anyone has collected all of the attempts into a single space.