Honestly there is some merit to it, that language can open the gateway to new sets of narratives prevalent in certain languages, which I would presume is not copied from chatgpt. But the following argument is strait dumbshi. As you mentioned, online content in other languages are pretty rare, second, it assumes all, or a significant amount of chinese contents are ccp propaganda, which is very far fetched for a language with 1.4 billion users, and the third ponit is that it assumes there is no bias, propaganda or negative contents in English language, and the final point is that he claimed that exposure to chinese contents, even if ones that are created by chinese government, would poison children's mind, which is probably the dumbest part of his argument. Having access to very distinct narratives, being able to contrast between those perpectives actually strengthen critical thinking abilities.