Since the AC3 audio track doesn't change the content of the episode itself, I’ll give you a review of the episode as it aired, plus a note on the AC3 version's technical quality. Plot summary: The teachers return to Abbott for a mandatory "development day" before students arrive. Janine is eager to implement new initiatives from the district, but Gregory (now a permanent substitute) is skeptical. Meanwhile, Ava tries to avoid doing any actual work, and Barbara and Melissa deal with a new, overly enthusiastic teacher.
It sounds like you're looking for a review of ("Development Day") — specifically the version with AC3 audio (Dolby Digital). abbott elementary s02e01 ac3