In my opinion the paper shouldn’t be take down. Instead a note should be added noting the concerns with the pre-print and that’s it’s likely fraudulent.
Edit: Since the paper has been cited, others may still need to reference the paper to determine if it materially affects a paper citing it. If the paper is removed it’s just a void.
Edit: Since the paper has been cited, others may still need to reference the paper to determine if it materially affects a paper citing it. If the paper is removed it’s just a void.