Yes but the evacuation is not called for by the captain via the P.A. until the Engine Start Levers are positioned to Cutoff.
Doesn't this action achieve the same result?
It's a good question Global TM. As Jhieminga touched on, perhaps it's one of those things where Boeing are damned if they do, damned if they don't. Possible reasons for evacuating an aircraft are many. All are obviously very serious. The number of scenarios where pulling the fire warning switches and firing a extinguisher bottle are numerous enough to warrant it's inclusion on all occasions, just to be sure.
However it does seem like overkill at times I agree (when performed in the simulator).