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It would not be a deep stall in the traditional sense, however any aircraft with a moving horizontal stabiliser can potentially mask the elevator, which has the same effect as the wing masking a t-tail. Stall recovery in that case will involve moving the horizontal stabiliser as well as the elevator.

One will notice that almost all jet transport aircraft will have takeoff range that the horizontal stabiliser is effective over, not having the horizontal stabiliser set in this range for takeoff could make the elevator potentially ineffective, hence it is an item check during the walk around and pre takeoff.

Keep in mind that ACARS messages are not sent sequentially when problems are reported, but according to a priority logic when multiple messages hit the que at near the same time. Folks with detailed knowledge of the A330 systems have said they expected several additional messages to have been received based entirely on those actually received.

The first ACARS message received was the auto pilot was off
The fourth and fifth messages sent were the Captain and F/O PFD SPD LIMIT warnings
The 10th message received approx 1 min 11 seconds after the first message was a fault on rudder trim (Rudder hard over?)
The 13th and 14th messages were HARD failures of the Pitot Probes
The last message received 4 minutes and 16 seconds after the first was ADVISIORY CABIN VERTICAL SPEED

The last being presumed to indicate that the fuselage had broken apart until the evidence recovered from the ocean showed that the oxygen masks had not deployed and there was no indication of decompression. It is this last message that provides the basis for the assumption that the entire event took 4 minutes. We don't know that.

It is now assumed the last message indicated the aircraft was descending with such negative vertical velocity that the pressurization system was unable to equalize cabin pressure quickly enough.

The aircraft acknowledged receipt of a verification message of the last message about 2 seconds after receipt - there was no further communication (The ACARS transmission process included four back and forth verification hand shakes between the receipt center and the aircraft).

We also know that one gap in the nessage sequence of approx 31 seconds was due in part to the difficulty of maintaining reliable satellite communications by the automated systems. It is assumed that additional messages were in the transmission que by never sent due to abrupt termination of the event that occured.

You obviously know far more about jet transports and the specifics of this crash than I do. The only T-tailed aircraft that I have personal knowledge of is the Piper Tomahawk. I have no doubt that your explanation of the "deep stall" and loss of horizontal stabiliser authority could have been a factor.

My brother was a check airmen for one of the airlines he worked for. I got to play in one of the big simulators with him on one occasion. It was very important to fly that simulator by the numbers, when I tried to land the simulator without using the instruments, the seat of my pants didn't work out well for me. I think these fly by wire complex aircraft do tend to insulate the pilots from the basics of flight and maybe that can become a problem at some point.

The inverse can be a little humorous. I have an old Rogallo style hang glider that can be towed behind a boat. I tried to get my brother who is a Captain for a major airline up in it once and it sort of freaked him out. It is basically a big kite when towed behind the boat. We use about 500 feet of line; it comes off the water at only 15 mph, less than 10 mph when launching into the wind. Unlike a parasail you can control its altitude and guide it from side by side and even release from the tow line and land on shore or soar the ridge lift from nearby cliffs. My brother was certain the glider was going to drop out of the sky and kill him at at any moment. He was however the first one to test fly my Skypup ultralight which has no flight instruments and loves it.