As shown by Zorla here the AOE revive has a cooldown.
This really doesn't seem fair, reviving multiple teammates is very situational and every other medic has no defib cooldown time so they can arguably revive more people in one room than Guardian can, i really don't see the need for a cooldown. Given that the maximum cooldown looks to be around 14 seconds what happens if you miss a revive or the person you are trying to revive gets jibbed? You just stand around watching your whole team die in front of you. Seems too far, or is it just me?