It's a thread that's been done before, I'm pretty sure. Many did come to the US, of course, but if you're talking about all those who eventually left Europe IOTL and ended up in Israel, then I'd say that's an awful lot of refugees to absorb in a generation. Unlikely, though NOT ASB by definition. It would certainly give rise to a wave of the same sorts of ethnic tensions and unrest that have accompanied every other wave of immigration here, only on a very grand scale. It might put off or simply butterfly away the foundation of Israel, which would be a very big impact of course.
But you have to answer the question: Why would the Zionists behind emigration from Europe prefer entering the USA to having their own home in what they considered God's Promised Land?