That is exactly it. Antisemites figured out a while back that they could say whatever they want about Jews as long as they swap out the word Zionist. This has been a feature of white supremacy for ages. It used to be “people with big noses” or “people who wear hats” or even “bankers,” or “globalists.” The latter two are more similar to the use of “Zionist” because they represent actual groups that people criticize. That gives more cover to the actual antisemites.
This is actually a good thing, because it removes that cover from bigots who want to hijack the movement and hide behind it.