Yeah I can definitely see how the argument about "original semites" is coming very close to outright hatred and antisemitism. We have to be more conscious of the language we use than that. We shouldn't be making arguments in this vein but instead focusing on anti-colonial arguments. When discussing the colonialism of relocating European Jewish communities to Palestine there's no reason to be using this kind of "race politics" language.
The relationship between Ashkenazi jews and the communities that were already present in Palestine is not something I understand very well, and more broadly the history of Ashkenazi jews as a whole is something I'm only familiar with as it relates to early 20th century European politics. It's something I'd like to do my own research on from reliable sources to better understand how these kinds of arguments feed into genuine hatred of Jewish people.
I'm not as educated on the broader nature of antisemitic arguments as I should be. I appreciate you adding context to why some Jewish students feel unsafe with the discourse going on at the moment. Anti-Zionist action has an obligation to protect Jewish people as much as it has an obligation to protect Muslim people and ethnic Palestinians. Our goals ought to be to separate ourselves from race hierarchy and protect human rights for all. It's critically important that in advocating against the Israeli government and the IDF that we do not tolerate anti-semitism in any form and that we reject the support of ant-semitic people wherever it appears.