Then a murder will occur
I feel like that would be just inconvenient and would ruin what the author built up till this point. So to say, it's pointless, there is no way this could get any more worse whilst having this really really hardly built structure and heavy atmosphere. There is difference between too much drama and just enough drama. A lot of authors tend to go too far. He(she?) made everything perfectly, gave a little of this, a little more of that, but he didn't turn this story into a powerpuff girl.
I also have that theory but I don't think it's in a way that the whole school finds out if not the group of friends, since apart from Haseol it would be interesting to see the reaction of Nari and Jinwoo who also suffered bullying and harassment
I'm so sure this monster still has the photos of Yeonwoo and is going to use them to create drama, it's obvious !
(It's not a spoiler, just a theory)