"rms" as he's preferred to be called for decades, has repeatedly proven quite correct about technology freedoms. This seems to be another case where he is correct, but will mostly be tuned out becuase publishers think that they, individually, will benefit from reducing their client's freedom and protection.
The individual data of purchases and of personal interests and subscriptions, and even data on interest in particular articles, is being collected and analyzed to tune advertising and to provide links to content the publishers wish to highlight and wish to ease the reader's access to. The data is also being resold, allegedly as metadata but far too often as raw data, to anyone who can pay for or _trade data_ for it. The result is a quite amazing loss of privacy due to this data harvesting. This loss of privacy is _dangerous_. Government interest in political speech and membership always has to be balanced between a good government's desire to know the citizen's real needs and desire's, and a dictator's need to strangle opposition of any form.
Unfortunately for what rms proposes, targeted advertising _is_ effective for increasing advertising effectiveness for the businesses that provide it. It does not necessarily increase _profit_. Many such schemes are done quite poorly, so poorly that subscribers leave the site. Slashdot almost fell prey to this kind of advertising over content approach to publication, when they tried the new layout and it was roundly rejected. But there are _many_ jobs of advertisers, and a _lot_ of marketing money, tied to targeted advertising. Buyer anonymity interferes profoundly with that and will be battled in the boardroom and in the courtroom. If it goes to court, it will be battled with "think of the children" and "war against terror" claims that genuine reader anonymity cannot be permitted.