Reports from the #chu2koi interview in Megami Magazine:
Relating to the new episode:
-There's been no progress in Yuuta and Rikka's relationship. Rather, it seems to have gone backwards a little bit.
-The reason they didn't depict a certain scene that was present in novel 1 was to follow one of the rules of the romantic comedy: "Make it indecisive."
-They wanted to emphasize Kumin and Isshiki's relationship to feel like "come on, there's nothing down that path."
-Throughout the story, Isshiki tried his best to find a girlfriend, but the invisible hand of God interfered.
-There's many happy scenes with Dekomori and Mori-Summer. It's possible to say their relationship has advanced.
-The new episode is definitely something not part of season 1 or season 2; it's an episode to bind the two together.
Relating to the second season:
-While it won't be emphasized as much as it was in the Lite episodes, comedy is a big part of season 2. However, they're still thinking about what the core of S2 will be.
-They plan to depict "How do you fall in love with a chuunibyou girl" in S2.
-Originally, S2 was to start around New Year's Day, but now it'll start around March.
-Compared to S1, S2 will have a more comfortable progression of time (umx note: ie, no random month timeskips).
-There may be replacement of characters and setting changes.
-Kuzuha and Yumeha may not appear at all. Touka's also really difficult to fit in.
-There's no plan to touch on the relationship between Rikka and her family. While things still aren't well with her grandfather, they don't plan to pursue that route.
-Kumin's family accidentally appeared.
-They want to introduce new character(s) without it getting muddled or turning into a love triangle. It's supposed to be a laid-back chuunibyou comedy.
-Right now, they think it's fine for ZAQ and the circle to sing the OP/ED respectively.