I've been doing a lot of digging into this, and unfortunately you do need to install several components to add it, plus the problem of getting the parts properly calibrated. I have an 22 RST that I've been playing with adding this on.
Currently I'm waiting to find either a wrecked Tahoe with these parts, or massive pay increase to afford it all lol.
At a minimum here are the parts that need added:
Long Range Radar Sensor Bracket and Sensor (located behind front bumper on passenger side) RPO code B233B
Front Fascia Harness (the connector for the long range radar sensor is not present) - includes connectors for all the parking sensors, grille camera, and LRR sensor.
Image Processing Module, Bracket, and Harness (located in rear hatch area on passenger side rear pillar) - On my Tahoe, the rear hatch/cargo area harness does not have connectors for the module. RPO code K124. This module mounts OVER the SRS module.
You may also need to change the Front View Windshield Camera as there are 2 different part numbers.
I'm finding is that most dealers are unwilling to give part numbers out over the phone when you call in. Of the 3 dealers I have, only 1 is willing to actually give me the part numbers.