I’m not sure about the medical journals but some of the others actually have page charges (the author’s employer pays for the article to be published).
I’m not prepared to say the journals do nothing. They do coordinate the peer review, as is pointed out in the Aoki letter.
The way that I understand it is that the medical journals are petitioning the government (Conyers) to make it illegal for the researchers to send their research to anyone else for publishing after they have sent it to be peer reviewed. If the journal coordinated a peer review, that part should not be reprinted but the researcher should be able to do anything they want with their own work.