Good catch! On closer inspection it does sort of look like a pipe and not a motor. If he has a 2LT then, yes, he would have cooling seats, but I think that is a fan under the seat.
That's the male side of a large connector to carry the wiring from the body harness to the seat controls/motors.
You would need to release the red lock, then unplug it to remove the seat. Every C8 has it.
It starts to show a bit when us tall guys put the seat all the way back.