"Stow the boards, Thrust to maximum,
I note the AA pilot advice was to first "stow the boards" by which one presumes he means retract the speed brakes first.
In contrast, that personal advice perhaps for his own aircraft type, is at odds with the windshear advice published in the the Boeing 737 QRH . There, it states the speed brakes are retracted
after the autopilot is disconnected, max thrust is applied and after rolling the wings level, and rotating towards an initial pitch attitude of 15 degrees. Of course all this happens very quickly.
The GPWS pull up manoeuvre is slightly different in that the initial pitch attitude is 20 degrees but the speed brakes are still retracted in the same order of events as the windshear escape manoeuvre.
The 20 degrees attitude was introduced after the Air New Zealand Mount Erebus crash when the DC10 hit Mt Erebus following a GPWS warning. At the time the GPWS pull up policy set by the major manufacturers was to select go around attitude of 15 degrees. Later research into CFIT accidents revealed that statistically 20 degrees gave you a better chance of getting away with it.