[hamiltonkibbe]

I think the whole point is that there is no code (firmware or otherwise) driving the switch. I guess it depends on your threat model, but if you don't trust apple's hardware or firmware to disconnect the microphone, you can't trust their hardware not to have another microphone somewhere else that isn't advertised and is on all the time.

I'd take the term "hardware disconnect" in this sense to mean that there exists no program that you can run on any of the processors, or no bitstream you could load into any FPGA on the device that would be able to enable the microphone when it shouldn't be enabled, eliminating the threat of malicious code enabling the microphone