If you can help millions or billions of people by turning a horrific event that already happened into something much more positive, I don’t see the issue. Helping people would reduce the chance of such events in the future and make these past deaths far less in vain.
Not using this potential would be like a people throwing away incredible technology left behind by an enemy after a war. The war was a crime and we emotionally want to disconnect from it. Yet we understood discarding potential technology that could help your own people is an additional crime and mostly based on emotions.
The Nazis left behind incredible technology that was created with slave labor or unethical experimentation. Not keeping and using this technology for good would have been an additional crime against those dead people.
We are talking about incredible world saving medical and military technology. Something that stopped pandemics and soviet conquest of the earth. We are talking about reducing suffering and giving freedom on a global scale. This is far different from using crime victims skin for something vain like a “lamp shade”
It violates the principle of the integral good.
Its an old Question.
Aquinas answered it in 1485.
First Part, Question 48 Article 4
Does evil totally corrupt good?
https://www.newadvent.org/summa/1048.htm