The only piece that not fit in puzzle will be rupture of FDR recording. Cables are at the right side, and any evolution you described are well into time frame of discretization on FDR.
Just a reminder of how the tail came off, the blast appears to have caused an instantaneous transverse failure across the crown of the fuselage at a frame forward of the aft doors.
If the wires transited that area, and were not already destroyed by blast debris further forward, the separation of the fuselage would have parted the wires. Wires just do not stretch.
