2 things:
Are you saying that someone who cheats will forever be an unethical person? What about teshuva?
Also, generally ethics courses have nothing to do with learning how to be ethical. Besides, there’s enough gray area in the field that no one can really define it- the names you mention all argue about it. For instance, Kant said Truth is the ultimate morality, that to lie is always immoral. But we as Jews do not believe that. We know Hashem Himself lied to Avraham once in order to spare his feelings. According to Kant, if your wife asks you if she looks fat in this dress and you say no (even though she does), that is immoral. Hillel would say you did the right thing.
The class will probably focus on the different philosophies of ethics, not “how to be ethical”. However, be prepared, some of that WILL conflict with what we believe as frum Jews. I suggest you find a Rav to talk to for when/if any issues come for you during the semester.