I'm not worried though and thanks for caring. I'll find out when the movie gets released. It's all fun speculation as far as I'm concerned. No one has a copy of the script so game related or manga related spoilers may or may not be relevant to the movie.
Images used in the teaser can mean almost anything that the director wants the audience to think to draw you in and then he can totally give you a 180 degree turn in the theater. He probably has to give a fresh interpretation imo since Clannad in theory should have had a wider penetration since it wasn't an eroge title. There is no real incentive to go to the theater if the outcome is assured and a TV series is broadcasting in the same year imo.
My Kanon avi is a good example of this. That scene was not in the TV series at all except the OP.
Mental exercises are good for the soul imo.