This is what I am trying to argue, that this is not realistically possible. You can have a situation where you will find 0 policy or legal government documents or statements that say that this moral position is to be taught, yet the curriculum, assessments and resources will unintentionally strongly suggest a narrow set of moral positions to the students, and most students will end up adopting something from that set.
Going back to my example of the biology course. Are you taking the position that the teacher not discuss ethics related to genetic engineering at all? That is already a moral position: students will learn that worrying about morals when you study technology is not required.
If morals are to be discussed, then the teachers are usually not experts in the field. Hence, they usually use resources suggested by the state. The state will suggest a small set of resources, and try as much as you can, those resources will only discuss only a few moral positions on genetic engineering. Ultimately, students will be taught these and they will adopt one of them.
The generic mistake you are making in your argument is forgetting that the null policy is also a policy.