I think
guiones has it right. Reality is just being restated. As you fly higher, the reduction in max. thrust available means that the speed at which you "fall behind the drag curve" increases, possibly to well above the stalling speed. At that point you have no choice but to descend (the aeroplane will do it for you), either by maintaining the same IAS and waiting for the thrust to come back
or by reducing pitch (and drag) and trading some potential energy for kinetic (height vs. speed) to get back earlier to a thrust>drag regime.
At progressively higher altitudes, stall recovery moves steadily towards the technique you would use in an unpowered aircraft, compared with lower down where minimum height loss is more important. The training doing the rounds at the moment may be because previous exercises concentrated more on low altitude mishaps?