Both CX and KA are sending aircraft out of HKG to outports for two reasons - 1) to protect the aircraft from potential typhoon damage 2) for crew and aircraft to be in position to return to HKG as soon as conditions permit (at this stage looks like late Monday afternoon). Hence if you check the arrivals board, you'll see all the afternoon/evening flights departed but the return sector was cancelled. CX will have around 25 aircraft, KA less than 10 in HK to ride out the storm.