Pink's body wanting to go to school and the dating minigame taking place in front of one is a trope, yes. Both for dating sims and the magical girl genre. But there's another layer to it that hits us pretty hard.
Mad Mew Mew in UNDERTALE didn't find her ideal body until someways into the events of the game (compared to Mettaton who's been in his body long enough to build a corporate media empire in the Underground). Pink in Deltarune could only possess an inanimate figurine until it sprung to life as a Darkner in Chapter 5. All to say is that neither version of Maddie figured out how to make this work until recently in their lives.
As a trans woman who cracked her egg at some point in her adulthood, we often wish we could have grown up this way. To know what it would have been like to be a girl from the outset, getting the care we need before our biology mangled our body, getting to know our family as a girl and not feel like we're trespassing the image of us in their minds.
So we feel that Pink's fixation on school is reflective of that yearning for a past that never was.
"I wish I figured this out sooner."
"I wish I could have loved myself enough to love others."
"I wish I learned these things in a simpler time."
One of Maddie's major conflicts with her new body is that she feels like if she starts loving herself and Pink, she'll lose herself. Accepting these feelings and desires when you've spent you entire life in this haze of self-loathing is hard. Doubly so when you've already built up a life and reputation as what you were assumed to be. Quadrouply so when you know you can't change how you grew up.
Only how you grow going forward, with these feelings.
