Ah ha! Further down the same page from my previous link. I knew there must be a connection.
In 1966, the AMA approached the publishers of American Aircraft Modeler (AAM) magazine about the possibility of incorporating a section called AMA News into their magazine rather than printing the small but costly MA. AMA members received AAM featuring AMA News as part of their membership beginning with the July/August 1966 issue and ending with the March 1975 issue. AAM went bankrupt in February of 1975, leaving the AMA with no means to communicate with its members. AMA officers realized that a magazine rather than a newsletter was more beneficial to AMA members, and thus resurrected MA as a magazine. To this day, AMA members continue to receive MA as a member benefit.