I've never understood this. Isn't it always possible to detect unsanctioned network traffic. Sure, most people don't. But all it takes is one person to spot an errant packet and a malicious actor's cover is blown. What purpose could possibly be served by putting code into firmware that gives itself away by generating network traffic.
Hacking firmware is another matter. But a vendor distributing malicious firmware code that generates network traffic? Not wittingly, it doesn't make sense. Of course if it's for some sensitive piece of machinery and the vendor has been compromised. But then if you're buying sensitive parts maybe you should be extra-cautious to ensure they operate as intended. But consumer hardware? I'm not seeing it. Call me naive or not tin-foil-hatty enough :)
You don't have to create additional packets to transmit additional information. You also don't have to transmit by default. So the detection model isn't "anyone dumps packets", it's "someone actively being monitored knows exactly what to look for".
Hacking firmware is another matter. But a vendor distributing malicious firmware code that generates network traffic? Not wittingly, it doesn't make sense. Of course if it's for some sensitive piece of machinery and the vendor has been compromised. But then if you're buying sensitive parts maybe you should be extra-cautious to ensure they operate as intended. But consumer hardware? I'm not seeing it. Call me naive or not tin-foil-hatty enough :)