While I don't agree totally with the story. There is some truth in it. A very large or several large fires could tax the resources needed to fight them. In no way do I think it will be the worst fire in US history. Another "Black Saturday" is possible but not likely with today's laws and resources.
No one can predict the future. But just think. Five years ago if somebody wrote that a hurricane would merge up with nor'easter, make a "left" turn and slam into the NJ coast all during full moon tides. I would have called them crazy. Nature constantly amazes me but trying to predict it is impossible.