As the VS/Rudder assembly is recovered and photography is available, it seems reasonable to analyze it as it appears.
In one image, I continue to believe the most forward mounting has remained in place, at least in part. It appears to be folded under the port side of the VS root at the front, just aft the dorsal fin attachment.
If so, and concluding an airborne (airflow induced) failure to port, the a/c was at the time yawed left. If so, it is reasonable to also consider a slight roll left, due to asym lift and differential sweep relative to airflow.
If true, that the a/c yawed left enough to fail the Vertical components, the roll will also introduce an exaggerated AoA HS relative to the airflow, which may have failed the HS/E on the starboard side. If the VS/R and HS/E (starboard) failed together, the damage to the base of the Rudder and the extreme damage to the aft mate (VS) would follow.
If the Rudder was perceived to be unresponsive (to the PRIM parameters) at this point, it might explain the Rudder message in ACARS. It might also explain the sequence of other data, including PRES. The possible failure of fuselage structure with HS loss certainly involves the aft pressure bulkhead.
Now the a/p disc. Involuntary, and purportedly due to unmitigable (a/p) control limits, the turbulence associated with its disengage is so far unknown. Grabbing hold of the now hand flown controls may have been quite a challenge (sic). With the disintegrating data on the glass and utter lack of cues..... At this point, we're back to a/p versus hand flying in severe(extreme) turbulence.
The question might be asked, Would it not be more advisable to be mentally flying the a/c along with the a/p up to a manual disconnect?
If surprisingly left with a/p unable to perform, versus hand flying well in advance of such time, what is the proper course?