The airport has four arrival gates: the domestic arrival gate or main building, terminal 2, termianl FBO and terminal 3. All of these terminals are just that, arrival terminals, and do not have any restaurants, bars or places where you can sit and wait for somebody else.
Now, the domestic arrival terminal and arrival terminal 2 are close together and you can walk from one terminal to the other. Arrival terminal FBO is a totally different building and too far to walk to the other three arrival terminals the same goes for terminal 3 however, there is a FREE trolley that will take you from terminal to terminal. This trolley IS NOT a scheduled trolley it waits until it gets full and then it goes to and from terminals.
The easiest way to wait for somebody that is arriving on a different flight is by waiting outside their arrival terminal. In other words, whomever arrives first has to wait or go and meet the other arriving passengers.
NEW -Outside arrival terminal 2 and arrival terminal 3, there is a waiting area/restaurant called the "Meeting Point". That is the best place to wait for an arriving passenger.
OFFICIAL - CANCUN AIRPORT TOP AIRPORT IN LATIN AMERICA & THE CARIBE
"ANNOUNCES TOTAL PASSENGER TRAFFIC FOR OCTOBER 2014 UP 15.8 % YEAR OVER YEAR"