> I don't think I have the right to insist they supress these beliefs, as long as they're not trying to harm me with them.
The argument from the trans community would be that misgendering and encouraging other employees to misgender them(which will happen if the belief is propaganda-ised) will cause significant emotional harm, risk mental health, cause problems in fulfilling job etc.. I'm not sure about how true this would be, as I'm in the closet and I'm a bit indifferent about what other people think, but can imagine it being very difficult for others.