I want to be fare to Google but their response was not satisfying to me. There should be no leakage of students' data that will persist and have an effect on students' digital (and physical) lives later in life. I side with the EFF on this issue.

In the comments, a parent advises their kids to only use their Chromebooks for class activities and never for personal email and web browsing. Great advice, and should work fine for children with privacy respecting smartphones.