BEagle.
That is the part I understand.
The ATR has two trigger values of AoA for the stick shaker; 12.5 for normal and 7.5 for icing conditions. The Icing AoA comes on when you select level 2 (anti-icing).
The aircraft will also give a Master Caution for Ice Accretion when actual accretion occurs.
You must have seen the ATR ice tests. These show the procedures to be safe.