This fall there have been a lot of brown leaves or no leaves at all on the oaks. What could be the cause?

During wet years such as this one (2017),  oaks can contract a disease called oak twig blight, which is caused by the fungus Cryptocline cinerescens.   This can result in significant foliage dieback; however, oaks easily recover from this disease.

This fall there have been a lot of brown leaves or no leaves at all on the oaks. What could be the cause?