I don't want to say for 100% certain that the osama letter thing is part of this pivot but the timing is sus. My take on that letter is that the antisemitism contained within it could disconnect anti-zionist jews from anti-zionist movements which makes it very dangerous.
We all know already how much antisemitism benefits zionism.
They are still making a mistake: They think it's Hamas' (or Iran's) propaganda that is shifting the tide, but it's simply more access to information. It's the same thing with cops; video is so much more powerful and viral than a few half-assed PR statements behind a podium.
Like the boy who cried wolf, nobody is listening to accusations of "Anti-Semitism" over bombing children.
The ADL chose in the aughts to link any critique of Israel with anti-Semitism, and it's becoming more clear how bullshit it is. People learn.
Also, most non-Jewish people who support Israel don't really care about anti-semitism