This has been a claim for a long time. The “no smoking gun” “theory” which goes something like “there’s no direct evidence of Hitler planning and directing the Holocaust therefore it can’t be pinned on him/Nazis broadly.” The idea is it was overzealous careerist types like Heydrich who twisted the words of Hitler (who wrote and spoke extensively and explicitly about extermination of the Jews…) and, yeah, essentially did the Holocaust without Hitler’s full knowledge to impress him or whatever. It hinges on a semi-truth that many top Nazis were careerists sucking up to Hitler, however that doesn’t absolve them nor him of genocide…despite right wing logic-bros’ efforts. “Himmler didn’t really want to kill all those innocent people, but he was afraid he wouldn’t get promoted otherwise😔”

(Do I need to point out that this is obviously bullshit and I’m just explaining the “logic” employed by those who seek to “clean” Nazi ideology and Hitler by trying to separate him from the atrocities that he wrote about, spoke about and of fucking course knew about and actively wanted to happen? I remember going over this stuff in a college Holocaust course years ago under the Holocaust denial portion of the course, which the belief that “Hitler might not have known/approved of it!” definitely falls)