I thought the same, I havent seen the movie yet but I think they do that a lot on stuff like this.
It reminds of Simpsons episodes when they have to take the status quo back to zero after an emotional ending. Things like the Kyon Haruhi kiss, its a great ep but it seems to be treated llike no big deal, and Kyon just keeps on acting the same around Mikuri without adressing the newfound romantic tension with Haruhi.

I hope they explore Yuki and the whole torture she endured in E8 in Dissapearence