I really hate to speculate ahead of the proper investigation, but something looks a little strange so I'm going to risk being (probably rightly) jeered at and mention it.
The photos of the crash site seem to show and extremely low-energy impact. There are no signs of a horizontal velocity at all - the wings seemed to have burned out (as you'd expect), but they appear to have been essentially intact when they arrived at their current location. The forward fuselage wreckage is lying in alignment with, and barely disconnected from, the wings. There is no classical "arrowhead" shape to the debris field, and there are no scrape-marks in the ground where the aeroplane came to a stop, which seems to suggest it dropped vertically and hit perfectly flat.
If the forward section of the fuselage had detached (sending the CG aft) this could be feasible (as for the impact site of development Typhoon DA6 in Spain), but this would need a wing and tail to still be both together and well-attached. If the theory is that this aeroplane broke-up at altitude, losing most of its tail in the process, then the CG would have gone forwards and there would have been no opposing/stabilising effect from the tailplane. So I would have expected it to either settle into a vertical dive or (if the CG fortuitously ended up in a certain very narrow range) a steady diving glide [probably inverted, due to the effect of the wing camber]. The wreckage configuration isn't really consistent with either of these scenarios - am I missing something?
PDR