User blog comment:Dereviewer/Future Theories/@comment-24685871-20151003172356/@comment-27159736-20151004194435

If it were my guess it would probably be due to the amount of exageration in the trailer that made them its the last episode, Dipper and Mabel are known to be very close so seeing them at a distressed moment may mean the mark of the end. The birthday plan might be held at Candy's house but Dipper cant come due to experiment and upset Mabel.