JD-EE
Read the safety first article, it will explain, as I have tried to do, why the stall warning may have gone off.
I think, you reference to that part of it.
Typically, in cruise at high Mach number and high altitude, at or close to the maximum recommended FL, there is a small margin between the actual cruise AoA and the AoA STALL. Hence, in ALTERNATE or DIRECT LAW, the margin with the AoA SW is even smaller.
The encounter of turbulence induces quick variations of the AoA. As a consequence, when the aircraft is flying close to the maximum recommended altitude, it is not unlikely that turbulence might induce temporary peaks of AoA going beyond the value of the AoA SW leading to intermittent onsetsof aural SW.
Equally, in similar high FL cruise conditions, in particular at turbulence speed, if the pilot makes significant longitudinal inputs, it is not unlikely that it reaches the AoA SW value. For those reasons, when in ALTERNATE or DIRECT LAW, it is recommended to fly at a cruise flight level lower than the maximum recommended.
A 4,000 ft margin is to be considered. Then, for the same cruise Mach number, the IAS will be higher, the AoA will be lower, and therefore the AoA margin towards AoA SW will be significantly increased.