looks to me like those are just power and ground to the bcm, primarily for the airbagView attachment 417158
Notice the PNK/BLK wires both sides, your right on about the wheel heat, that would be a simple relay to setup.
none of them show heat there is voice, vol up/down, track forward/back, source (ohm shared ground to the radio for 2-way function (note the arrows)), the other side is cruise set/resume (ohm grounded to the bcm), on/off
am I wrong?