Jews started returning ti Israel in the 19th century. It was just a matter of time. There propbably would have been a few million more returning later but the Germans and the Craz had other ideas.
Actually, the Germans had no objection to the Jews going to Palestine. All most of them had to do was turn over most of their assets to the Nazis, and they were free to begin the journey. It was the British navy that blocked things at the other end. The policy continued until shortly after the outbreak of hostilities in World War II.