Not disagreeing with you, but I can foresee where some people might argue against it. Arguments like:
- They are just installing the commlink somewhere in the arm, that's just like a form-factor
- You can install components in the arm after it is originally installed so it doesn't have that wiring in it by default
Although in response to my own "Devil's Advocacy" I would respond:
Commlinks take up the same capacity [2] in a cyberlimb as a Smuggling Compartment, which by description can likely hold a commlink and more. By getting just the Commlink a) you are paying 2000 nuyen more for the cyber-implant version, and b) it is fully integrated into the wiring of the arm, not just a fast removable component.
ETA:
I did find a mention of difference between Cyberware neural interface and DNI, it is at the beginning of Augmentations in the Gear chapter (pg 451)
Besides their wireless functionality, almost all cyberware devices are equipped with a neural interface (not to be confused with DNI) that lets you mentally activate and control their functions. You can use this in place of wireless control, preventing wireless hacking, as long as all of the "moving parts" are connected to your nervous system. An item that has a wireless bonus, however, can only gain that full level of functionality if wireless functionality is active.
but nonetheless, this doesn't discount the idea that you can still get the full DNI functionality by installing an implant Commlink in a device that has Capacity.