Mm,
I agree that what you've found is exactly what will happen.
But I'm not sure I'd teach a pilot to do it that way. And there are two reasons.
When flying, in trim and hands off, a pilot will naturally tend to make corrections in order to maintain the desired attitude. When an EFATO occurs, there is a very distinct change in attitude, as you discovered. If a pilot is taught to "leave everything alone", there would be a natural tendency to leave everything alone, including the attitude. Only be conciously appreciating that there is a large attitude change, and positively effecting that attitude change, can you be sure that human factors don't conspire to override the natural tendency of the aircraft to pitch down, and the result will not be nice.
The second reason is a little more practical. Go and repeat your experiment, but this time, use a stopwatch to measure the time it takes to settle down in a steady descent. Now repeat the exercise, but instead of letting the aircraft take care of itself, positively select the gliding attitude, and time it again. You will find that it all happens much quicker if you do something positive, which a) means you get to your glide speed quicker, so glide further, and b) means you can set your attitude then move onto something else much quicker. Attitude+Power=Performance - can't do much about the power, but set the attitude and you'll get the performance you want!
Having said that, I wouldn't dismiss your experiment completely. One thing it does show is that little, if any, trim change is needed (in your aircraft, at any rate) to go from a climb to a glide. That will be the case whether you let the aircraft settle into the descent itself, or positively set the attitude. It might not be the case in other types, so it's worth everyone experimenting (at a safe height) so that they know what way to expect to move the trim wheel if they have an EFATO.
FFF
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