There has been research done on the efficacy of introducing students to animal ethics and them changing their behavior by (for instance) ceasing to eat meat.

It can be effective - not like high percentage of students effective but like it gets a few students to think and act differently when they weren't aware of the issue at all before.

So, there is some evidence that exposure to ethical issues that demand behavioral changes that run against social norms can work. It'd be wild to think otherwise, since that'd mean no one would ever rationally question social morality. But that happens a lot. Not always due to exposure in an ethics class, but similar kinds of exposure and training in general