I'm as adverse to reinterpretations like this as anyone but what might be more interesting or actionable would be evidence of what data Google are collecting and how Google are using this data.
How is that gonna work? You can't just sniff the traffic between Google and the students(SSL & stuff), and I very much doubt that Google itself will let you take a look in their datacenter.
You most definitely can sniff traffic between Google and students, this is widespread and completely normal behaviour at schools and also on many corporate networks. School computers have a MITM certificate installed which allows decryption and re-encryption, usually for the purpose of content filtering and malware detection.
My point is the insinuation that Google or other tech-ed companies are inappropritely classified as "school officials" which the allows them access to data to profit from is made. It's all speculative what-if without any substantive reporting. No where in the article is a comment "Google declined our requests for information" or "Google declined to comment". The closest thing is a general quote from an EPIC associate about tech-ed companies being hush about how they use their data.
Speculative what-if without any substantive reporting is the entire crux of the argument concerning Google as a steward of student information, including the original EFF complaint [https://www.eff.org/document/ftc-complaint-google-education]. The entire argument is one giant "what-if" scenario; Google is not the first major company to offer both private and commercial services (Microsoft and Oracle, for example, have both made decades of business on providing services to third-parties with competing interests and acting as a trusted steward of those parties' data).
Fortunately, the FTC is empowered to do the "old-fashion sleuthing" if they find the accusation has merit on its face.
That's fine but I'd expect if the issue is to be treated with any urgency we would have some sense of the problem. If parties are acting sensibly with data and self regulating then the urgency is quite less than top priority. Does it need to be addressed, yes but perhaps parties would spend some time to get it right before rushing to create privacy disclosures that will only add to the confusion.
Disclosing partner and vendor data usage to parents is likely a tricky issue for schools. My guess is the current loophole is more about laziness and lack of mature regulation than any insidious plan by Google to capture data about our kids so they can show more relevant ads.