It might be correlated to journals that charge $70.00 per paper. If the NYT publishes a story citing a journal, the journal may go back, see that the NYT never actually bought the paper and a journalist just got a copy from somewhere, and then try to sue the NYT. The 'study' may be a weasel word that is used to avoid this outcome. And yes, over one article this is frivolous, but if the journal waits a few years and amasses 100 instances where this happened, then the NYT may actually go to court.