Actually the anti-zionism comes from the Muncatcher Rebbe. His son actually left Muncatch after the war because he felt zionism was the only answer after the war.
It is foolish to quote Rav Elchanon Wasserman. While its true before the war he was against Zionism, and he was against going to the US as well, we do not know what he would have said in 1945 had he lived and staying in Europe was not a possibility anymore