PowerSchool is a Student Information System used by schools to manage REQUIRED (grades, attendance, behavior) data. The lawsuit isn't alleging any data collected beyond what I would expect a student information to collect. There is also no evidence that they sold any data.
"Cherkin, a Seattle mother of two, former teacher, and author of the new parenting guide "The Screentime Solution," is now the lead plaintiff in a class-action lawsuit that alleges the education technology giant PowerSchool is selling student data"
It looks like an anit-technology in education activist going after the deepest pockets.