I don't think there's much new here. The Vatican aided many so-called "nationalist" leaders from east europe to escape after the war. That some of these leaders had also been involved in atrocities may or may not have been known to all those who were helping these"refugees".
It is too bad that Pius XI did not live long enough to be pope during the war; he was not a man to have kept silent
(as his last, unissued pastoral letter, proved); and Pius XII was a man of different temperment.
But the origins of the holocaust were in Berlin (and in occultic societies which flourised in Europe even before the first world war), and not Rome.
It is an incorrect statement to say Pius XII was silent, as he certainly was not. He was a man of action and confronted the Nazis by word and deed.