flightdetent;
my understanding of the system is as follows
Single Channel ILS - Pressing TO/GA will disconnect the A/P regardless of W/S Warning (TO/GA after W/S Warning gives Pilot F/D Escape Guidance)
Dual Channel ILS - Pressing TO/GA will keep the A/P engaged.
Following a Windshear Warning;
Single Channel ILS,: Follow The W/S Escape(manually)
Autopilot disengages after TOGA Selection
A Dual Channel ILS: The W/S Escape
TO/GA will drop A/P to single channel the A/P will remain engaged
Follow the Escape Maneuver (Automatic Flight)
If the pilots are not satisfied with the performance at any stage, follow the Manual Flight procedure as published above.
That is my take on it
(open to correction)