Yes knowledge can be rather "static", whereas teaching must be very "dynamic"!
It has been over 20 years since TGM was revised. Prior to Kelley's untimely passing, he actively revised TGM as his knowledge grew. I would hazard to say that if Kelley were with us now, TGM would have been revised several times to take advantage of new technological information.
Do you know if TGM will be revised in any way to update it's content, because I would hate to see it go the way of Hogan's 5 Lessons? A scientific book such as TGM must be continuously revised to take advantage of new knowledge. I would think that all those instructors with masters and doctorate level qualifications could get together and help in updating TGM to include current scientific information on the golf swing.