I don't know about the AMA. I know the game day protocol, which includes an unaffiliated neurosomething consultant on each sideline as well as one in a booth with two trainers to assist him, was established after the league paid $765 million to former players because of concussions. It was enhanced after the first Tua debacle to what we have today. I know they take it seriously. The CBA contains the word concussion 182 times. The entire protocol and checklist were developed jointly by the NFL's head, neck and spinal committee and the NFLPAs similar committee. And that protocol and checklist are agreed to in the CBA by both parties. The part of the CBA just describing the game day protocols takes up 13 pages. Of course I don't know, but I think a little more has gone into it than just having it blessed by the AMA.
Also, to the point of helmets adding to the instances of concussions, FWIW my father, who played his high school ball in the '50s, has been saying this for over 60 years that I'm aware of.