I for one would kindly suggest to IATA that they checkout the dictionary as that most certainly is not a correct definition of the word “direct”, and IATA as far as I’m aware, have as much right to change the dictionary as you or I.
IATA can claim what they wish, the fact is the word “direct” means “Extending or moving from one place to another without changing direction or stopping” and taken directly from the Oxford Dictionary: “there was no direct flight that day”…ie there was no direct flight from Edinburgh to Dubai that day.
direct: definition of direct in Oxford dictionary (British & World English)