You've got this cluster of sensors around the mirror, right DJ?
I've looked through my files and I haven't downloaded the one for the actual screen change but I've had that cowl off several times to play with the mirror and route the dashcam wire etc. If you get your fingers either side of the mirror stalk and ease the sides outward the clam shell will separate. If you look at all of the sensors, they clip into the housing and all unplug from the wiring harness. It might be worth a call to the dealer but my feeling is that the glass guy is being cautious- some cars have the radar cruise camera up there which is adjustable. The CX-3 has it behind the emblem on the radiator grille. I think as long as you don't switch the ignition on while it is all unplugged, it should all boot up fine afterwards.