In any event, the accident files suggest that the problem is not one of people not noticing the throttle has retarded itself until the stall has occurred. And regardless of that, read the title of the thread again -- the PTS is what we're discussing here.
Got a hard citation for that first claim? I've never seen anything in the accident record other than "failed to maintain airspeed / departure stall". There aren't categories for "departure stall where engine was definitely producing full power" and "departure stall where engine was producing 65%".
There's usually a "engine was producing power determined by metallurgy" and maybe if it survived "throttle was found in wide open position"... sometimes.
But I think you'll be hard-pressed to prove that the accident record shows a hard difference between known power outputs.
I'm the one who brought up the point about creeping throttles, and more to the point, lower than normal power being produced.
The PTS is teaching you to recognize and pitch, but a good instructor will also teach that the throttle hand goes forward simultaneously to make sure that thing up front is firewalled
(we'll leave engines with throttle handles that can put them above safe operating limits out if this for a minute, but there's an Air Florida crew dead from frozen instrumentation who'd be alive today if they shoved theirs up).
You keep saying it's an exercise to teach about recognizing a stall when no more power is available. If that's the case, I say that particular change to the PTS should include wording to the effect that the student needs to confirm that they really are.
Recognizing is but one step. Pitch is the next. Third is "why?".
How many people know roughly how many inches of MP their engine will put out up here at my home base before they start that takeoff roll, for example? How would that person know if they werent producing full power? How would they know to abort before lifting off on a hot day?
(There's multiple ways to tell, not just MP. My point here is the change to saying "full stall" is fine by me, but we've all seen folks who thought they were producing full power on a high DA takeoff who left the mixture full rich. The few who get it together and figure it out while in the middle of "recognizing" that they're on the edge of a stall after liftoff when they can't get out of ground-effect, survive.
The rest go into the record as a "departure stall" accident because they're not trained in that third step... figure out why it doesn't have enough power. The PTS doesn't require it. And it does get very little attention at lower altitude airports.