after the tail breaks off , HS failure and APU cone breakaway become much less likely.
A HS failure on the other hand can result in APU cone break away but after the HS is gone the tail breakaway is much less likely.
thinking about your two scenario's ...
First one. After the tail breaks-off (cause unknown), while considering the beefy 6-point tailmount, will probably leave intact the 'basically strong' cylinder of the tailcone. So immediate THS break-up appears to have lower probablility. The plane only starts rotating a while later. Losing the THS comes only after an increase of the aerodynamic loads.
Second one. If the THS is wrung out of position (cause still unknown), and one side breaks-off as a consequence of that. It could well take away immediately the 'double-paperclip' connection rod that spans the THS 'manufacturing insertion opening' on that side. Which immediately and severely degredates the strength and stiffness of that cylindrical area. Which then would at almost the same time, put the tail and other side of the THS out of position. With severe consequences. Which could well lead to a parallel departure of both tail and THS box and other half of the THS. This scenario appears to run faster than your first one.
It is not even necessary for this to push out the APU unit ... there is a possibility that the APU is still inside the cone.
So at first sight i think the tail could still come off. And consider your second option more likely at this stage and with the 'evidence' we have at this stage in time.
Confirmation or rejection of these scenario's of course requires checking and matching of the sequence with the pattern of the wreckage on the ground.
The most probable scenario could then be used to point back at the originating events.
+++
My impression was that we see only one half of the double paperclip in the structure. But i have to go back to the pictures to look at that.