Discord has expanded its Hateful Conduct Policy to explicitly include prohibitions against misgendering and deadnaming in a policy update. Accompanying this policy update, Discord has also implemented a comprehensive warning system to enforce these guidelines effectively.
Regardless of your claimed allegiance, your interpretation of 1A is still incorrect.
As a private entity, Discord is allowed to decide what content it permits and what it prohibits on its own platform. Especially in the case of online harrassment, a “let’s talk it out” attitude will get you nowhere.