I call nonsense. Nowhere does it say:
"Charge the Dragon at 1st level." Nor does it intimate that challenging the dragon is even
required. And plot immunity? Please.
In fact, it say pretty clearly on pages 6-7:
"Characters can engage in several encounters while cultists and kobolds rampage through Greenest. The sequence of events that follow is up to you and the characters.You can present them with as many of the encounters as you want, in any order."
The only 'requirement' for Episode 1 is the Seek the Keep mission. Hoard does have it's problems. I even wrote a blog post about them. I also wrote another post about how to overcome some of those problems. But a lot of the complaints I've seen about the adventure are from people who seem to have skimmed the text rather than, you know, read it.