Your quote "I believe the 737 stick-shaker and stall alert are operated by the ADIRUs directly".
Your information is incorrect:
Two independent, identical stall management yaw damper (SMYD) computers
determine when stall warning is required based upon:
• alpha vane angle of attack outputs
• ADIRU outputs
• anti–ice controls
• wing configurations
• air/ground sensing
• thrust
• FMC outputs.
The SMYD computers provide outputs for all stall warning to include stick shaker
and signals to the pitch limit indicator and airspeed displays and the GPWS
windshear detection and alert.
Two test switches are installed in the aft overhead panel. Pushing either of these
initiates a self–test of the respective stall warning channel. The No.1 activates the
Captain stick shaker, and the No. 2 activates the F/O stick shaker. Either stick
shaker vibrates both columns through column interconnects.
STALL WARNING TEST Switches
Push – on ground with AC power available: each test switch tests its respective
stall management yaw damper (SMYD) computer. No.1 SMYD computer shakes
Captain’s control column, No.2 SMYD computer shakes First Officer’s control
column. Vibrations can be felt on both columns
Good. I was correct that it wasn't the FGCs, which was the main point, that the software BA is generating is not controlling the stall warnings.
Thanks for the correction, but it's the same outcome as far as STS and MCAS software is concerned.