I can't say exactly how your system processes the info , but I do know why there are redundant systems to cancel cruise operation .
My vintage system uses two air brake pressure sensor , (brake light switches) one in front brake system, one in the rear brake system, to feed into the wiring and cancel cruise . Because the last thing you need when you apply the service brakes is the engine going WOT ( Wide Open Throttle ) to try and maintain speed.
I guess if both fail ....
we're on our own , find the cancel button FAST.