Calling it now, the twist is either gonna be that Kyouka is Higana (or at least related to her somehow), or that Higana somehow became the big bad of the story (whatever that means).
My bet is more on the former, as:
1. Their near-identical hairstyles, apart from I guess the color.
2. How early in the chapter one of the rumors were about "people turning into rabbits", and I just don't see that being mentioned if it isn't gonna be important later.
3. Izuko didn't seem to be a wolf-person in the flashback, so it's likely that happened after.
4. In said flashback, something was happening to Higana when she told Izuko to run. I'm guessing it was some kind of transformation. To me it looked more like petrification, though there's no mention of that so I doubt it.