Jackets have been an issue in QF because of the current policy. The policy dictates that the Capt makes the decision whether or not they are worn, meaning that most crews will pack a bulky piece of clothing that may or may not be worn depending on the whim of the PIC.
This new policy gets rid of that. The new jacket is lighter, cooler and less bulky than the item it replaces. 95% of the time it will be worn from air-conditioned transport to air-conditioned terminal to air-conditioned aircraft etc etc, unless the temp is over 27 degrees.
It wont be a bulky item taking up space in luggage. Aesthetics aside, it is actually a sensible policy.