Interesting addendum (p286 of the report) on the original intermittent AOA sensor failure that triggered this whole cascade:
The resolver 2 of the AOA sensor part number 08-NCW-24YQ was removed for further examination at the Moog facility in Blacksburg, VA. A physical examination and analysis conducted on June 5-6, 2019 by a group consisting of representatives from NTSB, Boeing, FAA, Collins, and Moog. The failure mode was a temperature dependent intermittent open rotor that eventually failed to operate at lower temperatures.
Using CT Scans, physical examinations, and Scanning Electron Microscope (SEM) imaging, the open circuit was found to be a broken magnet wire on the rotor coil. A loose loop in the coil of the magnet wire had been epoxied between two different insulators on the rotor with different coefficients of thermal expansion for each insulator. As the rotor was exposed to cyclic differences in operating temperature over time, it is likely that the difference in the expansion rates of the two insulators induced a localized stress in the coil wire that led to a fatigue break in the wire that was open or closed dependent on temperature.