For transmitters, sure, that might work with a lot of caveats attached. For example, you need to repurpose wires on the PCB to act as antennas and then hope that the shielding around the elctronics will be transparent enough to pick anything up.
But getting the information to be transmitted is a lot harder. I don't know what kind of component this is, but I suspect that not a lot of PCBs have direct access to that kind of high level information (assuming that there is a kind of system bus that even passes such data around...).
I think in this type of business it is take what you can get as far as technology. A fuel pump PCB could be bugged one way, while a core flight control PCB could be bugged another. The bugs could also carry their own sensors. A simple pressure sensor could report altitude, and an accelerometer/compass could report motion. Those could be placed on the output stage of one of dozens of antenna or radar hardware. Even modulating a light bulb or LED slightly can transmit data that can be seen miles away.
But getting the information to be transmitted is a lot harder. I don't know what kind of component this is, but I suspect that not a lot of PCBs have direct access to that kind of high level information (assuming that there is a kind of system bus that even passes such data around...).