You don't have to agree with this take if it's not for you. I think its also equally valid interpretation that she didn't! The musical and movie do not explicitly state who wrote it. It is intended to never truly answer this question because, it truly could have been anyone.

Regardless of the motivation, Morrible is provoking Ephaba to get a reaction. Truly, how else do you cultivate a better environment than orchestrating it yourself? Create the perfect environment to make someone have the illusion of control.

Maybe Elphaba hasn't made enough of a break through, maybe she wasn't excelling fast enough. Or even the Wizard wanted to excellerate the final parts of his plan to unite Oz against the animals. Or even this was just a convient time that lined up with her lesson plan.

We've seen the classic mentor to student real talk conversation before, and this is how this scene is framed. However, second round watching it and knowing how Yeoh protrays Morrible, this scene feels orchestrated.

Because yeah even knowing her name is basically horrible, at this point we are supposed to trust Morrible as a mentor whos looking out for her students well being.

Honestly, the first time watching, again, she seemed concerned on behalf of a student who she knows is not able to focus on her lesson. Then giving her an opportunity to clear her head to eventually get to a point of focus to complete the lesson.

Even if its for Elphaba's own benefit, Morrible is only offering to help her because she knows how helpful to the Wizard in the future. So it is nothing but calculating when she brings up the incident in Dillamond's class.

Morrible is an extremely calculating antagonist. She is a very active part of the Wizard's plan to control Oz. She covers for Elphaba's initial outburst to control the narrative of who has power. Elphaba even explicitly confides in Morrible directly after this incident about how her powers manifest.

The way the film frames this moment for a first time watch read as concerned for Elphaba because of her lack of focus in her magic lesson. However, second watching makes it far more clear on the extremely blatant manipulation.

I could go on a whole thread of her performance alone. But the moment I will point out that made it feel very inexplicable the second time watching the movie was directly after the chalkboard incident in Dillamond's class.

Elphaba is whisked underneath her wing and given the validation she was never given by her family. And for Galinda, she gives pretty consistent rejection which she has yet to receive making both of these girls vy for her approval.

The Wicked Movie gave me an entirely different interpretation given how it was able to flesh out more of the off stage moments that made me believe it was Morrible who wrote it. Michelle Yeoh truly made such a spectacular performance in how she manipulated her students.

It's when they are being held accountable and dare I say, experiencing public shaming, that they shrink away from ownership of the act due to fear of social consequences

There is open resentment of animals that makes for this to be a relatively easy to come to the conclusion that someone thought this would be a "prank" or pretend to be cool. I've watched people do something atrocious and then refuse to own the fact they did it despite being prideful in the act.

It's never been a secret in the story that animals are not being as welcomed by society and actively being shunned by fellow Ozians. Combine with a university of privileged students, a cowardly malicious act is right up the alley for this demographic.

Tbh every stage performance I've seen, I always interpreted this action as any one of his students could have wrote it (except Elphaba) due to the rising anti-animal sentiment during the story.