#Googel is a mobile phone provider and could theoretically have installed #M2M profiles in the #eSIM on its #Pixel. Or update them over-the-air at a later date. I think what was meant was that with proprietary hardware in flight mode, you would only have certainty when the radio emissions are measured.

Of course, you still don't know if there is any unwanted data leakage past the #GrapheneOS operating system. This is one of the main problems with proprietary hardware. To find out, you would have to be able to read the encrypted 5G radio traffic.