Singapore Airlines KrisFlyer - does SQ call everyone who has checked in but hasn't shown up to airport?

Just curious. I've had two occasions where I checked in, and cut it close getting to the airport for a flight (both times flying from Australia to Singapore). They called my mobile phone both times (at ~1hr before flight time) to ask if I was still coming to be on the flight. I was pretty much the last one to dash through the lobby and pick up my documents.

Do they do this for everyone / anyone who has checked in but hasn't shown up? I was flying business both times, if that matters.

Is it just Australia? Lucky I had an Australian mobile number to give them -- I wonder if they would if it was a US number, for example.

Once when I checked in on the late side for IFC at LAX, the agent commented that they had been looking/waiting for me. They knew my name and were expecting me after my overnight connection. Another time I stopped in a lounge after an early morning arrival from my connection into LAX and when I got to the SQ FC check in counter at TBIT, the agent commented that my checked bag had already been transferred over to SQ. Usually they tell me in the lounge that my bag has successfully made it to the SQ flight.