IATA Wants to Shrink Carry-On Bag Size
You may be interested to learn this is part of a bigger "idea" for IATA to license bag manufacturers for bags that conform with the new standard and provide some form of IATA certified logo on the bag that will.... Wait for it.. Guarantee the bag can be carried onboard the flight.
IATA gets new revenue stream, bag manufacturers sell loads of new carry-on certified bags and we end up with the need to replace our carry-on luggage that no longer conforms to the "standard"..
Apart from the obvious business opportunity, this is in part a response to the unintended consequence of densing up aircraft to the point where the carry-on baggage storage bins can no longer accomodate the carry-on allowance of every passenger on an aircraft.