(can anyone comment on the projection icon)?
The projection icon changes to AppleCarPlay or Android Auto when a cell phone is plugged into USB.
At the time of production, the Android Auto software wasn’t ready but all the needed hardware was. So Cadillac put the hardware in the car and released information stating the software will come out later and they’ll update the car for free for a while. The software came out months later and dealers started updating the cars on the lot and the tech savvy customers who wanted it. After a while, Cadillac stopped offering the update for free and forced the dealers to charge for it if someone specifically asked for the Android Auto update.
To get around this, people with vehicles under warranty could go to the dealer with an infotainment complaint (real or made up) that would trigger a warranty software update to the HMI module. Any current update to the HMI module will also include the previous Android Auto update.
There are several service bulletins with CUE issues that require a HMI software update. The issues listed in those bulletins range from Bluetooth issues, blank screens, voice commands, and various odd glitches.