Can you explain where I'm misinformed? I can surely be misinformed about the workings of Lemmy. However, for GDPR you will not "win" it with a simple TOS or something like that.
If even Google can't make their Workplace to follow rules in such a way that Workplace can be used according to the AVG rules in the Belgian (well, Flemish) schools, I'm pretty sure that just saying "it's in the TOS" is not enough...
But again, no expert so I hope that I am wrong.
You are missing the point. A TOS can't fix it. If it can, they would have done so. And for GDPR, there is no difference between schools and genpop. A citizen is a citizen...