I am a new high school teacher, and I want to disclose the risks and limitations of learning in a classroom to the students, but my supervisor said I cannot do this. Other teachers must have their concerns and doubts from time to time. The concerns I have are that I think there can be undetectable bullying among the students in some of my classes, and I think several students will need to do certain things to prepare themselves for non-academic careers that have nothing to do with schools. Should I risk getting fired or should I just hope the students will be OK despite my concerns?
If you are fired you won't be able to help anyone.
But instead of being proactive in speaking with them, you can just be vigilant and deal with problems as they occur. If you maintain open communications with those who might be on the receiving end, you will probably hear about issues. If necessary you can take them to the supervisor.
But disobeying a supervisor for a new employee isn't likely to be especially helpful.