The author does not say say that MCAS works as a stick pusher, and does not describe it as if it did. He writes "When the AOA reaches a point without enough stall margin, the system adds some nose-down pitch trim. That pitches the nose down and gives the pilot the stick force to know that he is pulling too close to the stall margin" [my emphasis.] Given that the trim operates by changing the angle of incidence of the stabilizer, and apparently only provides feedback at the yoke through the aerodynamic consequences of the trim change, is that inaccurate is some way? Maybe the threshold is as much one of stability margin as stall margin, but that's not significant with respect to the issue here.