I have Rivens to kill Dargyns without being being affected by status effects. One of them requiring Archwing mode, the other not.
I have tried Inaros with Negation Swarm, and also Amesha's Warding Grace.
Mission was invite only, I was the host playing alone.
In Plains of Eidolon, the abilities are not completely preventing status procs.
I can see the status procs icons showing that Inaros was being affected by status procs - this happened several minutes after I had my Neg