Suppression was good in BF3, cause actual damage in BF3 was unrealistic, and you'd usually just end up respawning not far from where you died anyway.
Suppresion is not needed in Arma; damage in Arma is realistic, and much more consequential. I remember on one Arma mission where if you died, it was like a five minute helicopter ride back to the fight, if you could find someone to pick you up - sometimes the wait was alot longer. So if I hear bullets whizzing around me, I am already suppressed and running for cover - no need for a mechanism to force it on me, the fear of having to respawn will be plenty.