Most if not all passenger aircraft runs on auto pilot system in this modern age. Such systems have built in fail/safe measures, dependent on multiple onboard sensors to detect changes in heat, air pressure, etc, etc & with its algorithms, the auto system with SEVERAL FACTORS calculated at light speed, would do its job to keep passengers safe & aircraft integrity, & may even be better than Human pilot crews in decision making.
Thus, what SPOOKED the auto-pilot to take EXTREME measures as a PRIME DIRECTIVE to save MOST, if NOT ALL passengers lives & integrity of SQ321?
With all that sensor equipment, surely it would have a flight VISUAL camera of what laid ahead of the SQ321, let alone the detecting sensors data.....
In the end, the Human pilot crew did what was right - to take back control & DIVERT its flight towards Bangkok than to its original destination - Yangon Myanmar, to save lives & aircraft, than to take CHANCES to fly into the Turbulence Event......