Earlier quoted context omitted.
Using a person's name from before they come out as transgender is called deadnaming and is a tactic favored among abusive people. The polite thing to do, regardless of personal politics, is to simply reassociate the person with the name Chelsea Manning and move on with your life.
"Hi, I know this is a thread about someone's passing, and I'm gonna let you finish, but unless you adopt my preferred method of reasoning on this tangential, hot-button topic that I haven't even given you a chance to properly discuss, you're an abusive person. The polite thing to do is to think and talk the way I'm telling you to and move on with your life, because otherwise, you're a monster."
You're literally putting words in my mouth there.
I said that was a tactic favored among abusive people. That's not an accusation, that's an observable fact about how abusive people behave.
I choose my words carefully, y'know.