A disconnect doesn't have to move to be implemented in hardware. They describe the implementation in the article linked above:
> In each product with a hardware microphone cutoff, one or more lid sensors detect the physical closure of the lid or case using some physical property (for example, a Hall effect sensor or a hinge angle sensor) of the interaction. For sensors where calibration is necessary, parameters are set during production of the device and the calibration process includes a nonreversible hardware lock out of any subsequent changes to sensitive parameters on the sensor. These sensors emit a direct hardware signal that goes through a simple set of nonreprogrammable hardware logic. This logic provides debounce, hysteresis, and/or a delay of up to 500 ms before disabling the microphone. Depending on the product, this signal can be implemented either by disabling the lines transporting data between the microphone and the System on Chip (SoC) or by disabling one of the input lines to the microphone module that’s allowing it to be active—for example, the clock line or a similar effective control.
> In each product with a hardware microphone cutoff, one or more lid sensors detect the physical closure of the lid or case using some physical property (for example, a Hall effect sensor or a hinge angle sensor) of the interaction. For sensors where calibration is necessary, parameters are set during production of the device and the calibration process includes a nonreversible hardware lock out of any subsequent changes to sensitive parameters on the sensor. These sensors emit a direct hardware signal that goes through a simple set of nonreprogrammable hardware logic. This logic provides debounce, hysteresis, and/or a delay of up to 500 ms before disabling the microphone. Depending on the product, this signal can be implemented either by disabling the lines transporting data between the microphone and the System on Chip (SoC) or by disabling one of the input lines to the microphone module that’s allowing it to be active—for example, the clock line or a similar effective control.