I'ld love to mention something her about any speculation mention with regards to an autopilot commanded emergency decent.
This A320, with MSN lower than 5000 is still equipped with the EXPED button on the FCU. EXPED DES mode is available on this aircraft, while disabled on most A320 with higher MSN.
EXPED DES mode triggers a 4000-5000 fpm decent rate which would match the readout of FLR24, more or less.
For me this was commanded decent to 6800 ft and EXPED button pushed. Autopilot is on ATHR, AP1 on. There was never a deviation of its original flightplan. It follows the route constantly and very precise. Too precise for manual flight.
Unfortunatly at 6800ft impossible to surpass the mountains, reason why they hit ground at full speed.
The bis question is, was the initiation of the emergency decent the last activity of crew in cockpit?
Why no squawk 7700?