As many previous posts have summarised:
Until the rollback, the a/c was in a configuration of flaps, gear, thrust and AoA that maintained the g/s at the selected speed.
Thrust is reduced, a/p attempts to maintain g/s at expense of speed by increasing AoA while the crew is sorting out what is going on.
The drag from the flaps will accelerate the speed decay resulting from loss of thrust; so, reducing flaps will reduce the rate of speed decay at a cost of having to lower the nose to regain speed.
You then end up substantially lower, but in this case the resultant approach path fortunately happened to remain above the obstacle clearance slope until hostile structures and terrain were cleared.
In gliders a high drag approach is a steep approach. With certain flapped gliders, maximum flaps give you a very steep approach. A good way to get yourself in trouble with such a glider is to select more flaps early on final than will allow you to reach your desired touchdown point because decreasing flaps may require you to lose more height on final than you might have available
In contrast to jets, a glider with max landing flaps will approach substantially nose down until flaring just before hitting the ground -- same applies to a C-172 forced approach with 40 flaps. In both cases the airspeed decays very quickly when the nose comes up.
A jet with max landing flaps approaches nose up courtesy of thrust.
It would be interesting to hear of any simulator landings with max flaps and idle thrust from height.