Katomina slipped up and sent an Instagram story to her public account.
It says
"can they change the channel? I am doing manicure here."
Sorry for being dense but what is so bad about this?
She's one of the girls thought to be directly involved in Maho's case / one of the troublemakers. A better translation I found of the statement: "And here I am finally getting my nails done - I wish someone would change the channel". The way she worded it makes it sound like the graduation was an inconvenience to her. It also doesn't help her case that this was originally meant to be for her private account / close friends. Even if she meant no harm by the statement, the media is watching NGT48 like a hawk, and anything remotely negative can and will be reported on. The post was only up for a few minutes, but it was enough time for people to get screenshots and start spreading them on Twitter.
Demoting solves absolutely nothing. There's no teams, they all are on the same playing field. Like minaeshi said, it's just to save face. At this point, I wish they would just disband NGT48. They're becoming an eyesore.