And you can say goodbye about privacy if you integrate a phone capability, since phone modules run their own secret OS in the background, and who knows what they do.
First, some people are ok with that. If you're seriously that paranoid just don't get it. Modular means optional. Hundreds of millions (possibly billions?) of people around the world already own a cell phone, so for us whatever privacy concerns you might have are already present: if our phone is spying on us then it's spying on us, and another device which may or may not be spying on us in the same way is of little concern.
Second... wut? These modules have no microphone or speaker of their own, they depend entirely on the connected device to handle sound. If the Pyra isn't actively sending audio data then there isn't any way for them to broadcast audio data. If position data is a concern, GPS uses a lot of power and since the Pyra would be in full control of the power going to the module these signature power spikes would be very obvious, there'd be no way to hide the fact that the cell module has turned on its GPS without your permission. So the only information anyone could secretly gather is cell based location. This is unlike existing mobile phones where the system does not have to actively provide audio data, and cannot monitor power spikes; if you already own a cell phone, there is a significantly higher possibility of your privacy being secretly compromised than there would be if you were using a theoretical cell module in a Pyra.
And finally, if privacy is really a concern but you still need a cell phone, and you're so very paranoid about privacy that you have it turned completely off when not in use and only activate it when you absolutely have to, unlike current cell phones where you can tell them to put it into airplane mode but you aren't really sure if it's really killed all power to the radios or if they can't reactivate themselves somehow secretly, the Pyra will be in full control of the power supply so you should feel secure knowing that cutting the power really means the power has been cut, completely severed, no chance of a "secret OS" being used to spy on you.