It’s a good idea, but they have to convince the major carriers to let it onto their network, and if the carriers get pressure, they may do like the rest of the tech giants and not allow the phones. I doubt Gab has the ability to start its own cellular network, too. Companies like Qualcomm could deny them chips and a license to use the IP for a cellular phone. Then they just need to design their own OS to compete with Apple and Android, and convince all the app makers to port their apps to this new OS.
A pretty tall order.
I wonder: Will Elon Musk make cell phones and a Starlink-based cellular network some day soon?