Volvo have told me twice that City Safe doesn't need re-calibrating and I proved that to myself by trying to drive into a cardboard box!
What I understand does need re-calibrating is the lane control feature which vibrates the steering wheel if the car drifts out of lane.
My car doesn't have this but I can see a small variance in this systems camera position on a new windscreen could make a big difference at 10-20mtrs in front of the car if re-calibration of this system isn't done.