Is there any information yet that the composite structure, particularly around hinge points etc., may have failed initiating an inflight breakup sequence.
Only information available yet is that a major structural element made from composite (the vertical stabilizer) broke of the aircraft and is basically intact, indicating that it broke of quite early in the breakup sequence, most probably already far before the final impact. The point of fracture lies within the metal structure this composite part is attached to. See
This picture for example, the two aft metal lug fittings are still attached to the fin with some remainder of the according metallic fuselage frames still attached.
So sorry metal lovers, this time it does not look like a composite issue.