You're discounting the way business is done in the military. An industry leader would do well to announce a relatively irrelevant feature like longest duration

You're discounting the way business is done in the military. An industry leader would do well to announce a relatively irrelevant feature like longest duration if it impressed decision makers in the government enough to give the business more money. The really important tech beyond lighter than air ships that I mentioned in another comment is in-air refueling of UAVs. With that, any autonomous ship can be in the air until maintenance is needed. That is more important than the longest run of an efficiency craft. I am still impressed that the bombing runs on Afghanistan 6 years ago took off from America.