These switches interact with software or programmable, connected components. They don't physically disconnect the hardware in a way that only the switch itself can reverse.
Citation needed. I don't see why they wouldn't have made the slide switches physically disable the mics, otherwise what would be the point of using a physical slider switch? The whole point of the feature is privacy.
Edit: I hate people making claims with zero evidence, so here's some evidence for you: I just took apart my Google Home Mini. The mics are digital PDM mics, connected to a shared line (in stereo config), that goes to what is almost certainly an AND gate (tiny IC, can't quite find the part number, pinout matches a SN74LV1T00), with the other input connected directly to the mute switch (via some resistors), and the output to the SoC (via a resistor divider, probably because the SoC input is likely 1.8V logic). When the mute switch is engaged, the output of the AND gate, which is normally a TDM train (average half of 3.3V), goes to 0V. This is the output that goes to the SoC. So when the mute switch is engaged, the audio input from the mics is electrically cut off from the SoC.
