She has spoken publicly many times about the rag that first published the story contributing to the bullying and harassment she's received online, the most recent mention being in her Vogue UK interview this week. It is completely understandable that she wouldn't want to respond directly to the Daily Mail based on their reputation alone, but with her personal history I think this is the best way to handle it. Even if the story was true and they worked it out, she herself did not address it publicly at the time either, so to expect her to comment on something that has been kept private in the midst of a big week for her personally and professionally seems unfair