Hong Kong and Macau - possibility of meeting some one at arrival gate?

a friend' son will flight from US to Hong Kong alone (minor). Is it possible to meet his son at arrival gate? He is prc citizen from shanghai. If he take flight from shanghai to hong kong, can he meets his son at arrival gate before he exit immigration? I also research this and i cannot find answer. From Hong
kong airport map, most arrival is terminal 1. The arrival area seems one area.There is two exit gates A and B. arrival flights show only A or B on hong kong airport website. Where you can find which gate the airplane lands?

If the parent is already airside legitimately (i.e. recently arrived on another flight) then he could be waiting at the gate where the son exits the plane in most cases. The tricky bit is going to be finding out which individual gate the place is arriving at - I don't recall this being displayed on any monitors, so my suggestion would be for the parent to go to the airside transit desk for the airline on which his son is arriving, explain the situation, and ask which gate the flight will be coming in to.

The exits A & B are the exits after immigration and customs into the "land side" area. Arriving passengers can choose freely which of these exits they walk through.

I have found it difficult to blindly meet someone in the arrivals hall at the HK airport. Setting up a designated spot is the wisest option.