That’s news to me ... and I remember those years well.
“The Nazis ferociously attacked Pius XII for what he said during his famous speech on Christmas 1942. They went on record stating: “Here he [the pope] condemns everything we stand for and he has made himself a mouth-piece of the Jewish warmongers.” When Pius XII spoke in his allocution about “hundreds of thousands” of victims, there was no evidence at that time that the number of victims ran, or was going to run, into the millions. Cornwell accuses the pope of downgrading the Holocaust; however, he does not take into account what was known at that time.”
http://www.catholiceducation.org/articles/arts/al0039.html