I think the part that is bothering me most, is the high chance that the SCP and the principal will not face consequences proportionate to what they are doing here.
The response to their actions, to me, feels like state-mandated execution. I doubt the SCP will even be expelled--potentially not even suspended, and/or removed from her position. Same with the Principal.
And that does temper my enjoyment of this. I realize the MC sits as an absurd entity within the setting, but everything else around her should remain coherent. I would argue that unleashing demons upon a student for the sake of bullying her out of the academy should be met with considerable punishment if/when apprehended. So if that doesn't come to pass, it cheapens everything else--because it destroys any suspension of disbelief in the continuity of the world and how it relates to itself.
It's one thing for the MC to exist separate from the power structures. But the other denizens should still be beholden to them, or else the MC's extraordinary situation isn't actually extraordinary.