To be honest that opening felt a bit too rushed. The socially stunted MC who spent at least 20 years not being able to talk to strangers then suddenly able to give a speech where she owns the jealous girl and everyone claps? That feels too easy. The speech fit her chatacterisation (awkward, earnest and out of touch) but everyone's reply to the speech was way, WAY too positive. During highschool she was isolated to the point that she became a hikki. There is no way that a class that creates that type of environment would also turn around and unreservedly support the loser MC like that. It feels like wish-fulfillment at that point.
I am totally fine with the class choosing her as the rep, as she was the person who stood out the most.