My first computer had an unintended 'power on after power fail' mode, resulting from a short-circuited power button! I don't believe modern motherboards would

My first computer had an unintended 'power on after power fail' mode, resulting from a short-circuited power button! I don't believe modern motherboards would do that; they must be listening for their power button's state transition when it is depressed rather than simply checking whether it is closed.