What could Pope Pius XII have done besides nothing? No words from him would have changed anything other than the Nazis would then have gone after all Catholics as well as Jews, gone after and gassed all priests, all nuns, monks, etc. That's how insane the Nazis were. The words of Pius XII would have meant nothing. The only thing that would have stopped the Nazis was if the USA had dropped the atomic bomb on Berlin like they did to Hiroshima and Nagasaki.
Pius XII was a diplomat who knew if he said anything, not only would even more Jews be targeted, but also all Catholics. There was no option other than to remain outwardly silent, but work secretly to save as many Jews and to throw his support to those secretly trying to overthrow the Nazis/assassinate Hitler. And there are letters and testimony to show that that is exactly what he did do.
They are going to now paint Pius XII in the worst possible light. What isn't really know, and should be known, is that the Lutheran "church" in Germany and elsewhere in Europe applauded the actions of the Nazis, cheered the persecution of Jews. Lutheran so-called "bishops" actively encouraged anti-Semitic preaching in their churches. And of course, no other Protestant group in USA or Europe raised their voices to condemn the slaughter of the Jews.....and they knew all about it too.
Pius XII was a hero. He even risked his life in a plan to assassinate Hitler, Goebbles, Himmler, etc. All the masterminds of the genocide of the Jews. He did so quietly, without seeking praise.