We know for a fact that Hitler hated atheists and Nazis only recruited Protestants and Catholics. Probably this question is not too sincere anyway, however, I will use this opportunity to point out a common mistake.
“Atheist” is not an identity. It is lack of a religious identity and disbelief in God.
If Tom said “I am a Christian”, you would learn something about Tom, on the other hand, if Jullia said “I am an atheist” you would get to know what she was not, rather than what she was. Hence Hitler’s atheism would be irrelevant even if he were to be an atheist.
I know a lot about someone who says they are atheist:
1. Atheists are unable to think rationally. Atheism is after all the belief that everything just happened al by itself.
2. 99% of atheists are leftists who believe in myths like global warming, Big Tech censorship, a government run society, COVID mask mandates, LGBTQ pathologies as normal, removing God and prayer from society.
3. Atheists generally hate Christianity and the Bible with a purple passion. This is anti-1st Amendment, thus anti-American.
4. Atheism is an aggressive, leftist ideology that atheists would impose one everyone if they could.