Ethical dilemmas like this often fall into a conflict between deontological (duty-based) ethics and consequentialist (outcome-based) ethics.
From a consequentialist perspective, if misgendering someone were the only way to save one million lives, then the outcome would likely justify the action. Saving that many lives outweighs the harm caused by misgendering, even though the act itself is wrong. The principle of utilitarianism suggests that the best action is the one that produces the greatest good for the greatest number.
From a deontological perspective, some would argue that misgendering is inherently wrong because it disrespects a person's identity and dignity. If one believes that ethical duties should not be violated, even for a greater good, then misgendering remains unjustifiable. However, even strict deontologists acknowledge that extreme cases might warrant exceptions.
In real-world application, the situation matters. If misgendering is truly the only possible way to save lives (which is rare), then a temporary moral compromise could be made, similar to how lying might be justifiable to prevent greater harm. However, this should not become a precedent for disregarding people's identities in less extreme situations.
Conclusion:
In a life-or-death scenario where there is no alternative, a consequentialist view would justify misgendering to save one million lives. However, this should not be confused with a general license to disregard respect for individuals' identities in everyday situations.
