Twilight Ward does not change into Fury Ward because the coding of the 4 set bonus overrides the Fury Ward transition.
Fury Ward works rarely when you have the 4 set bonus from pvp.
I put a ticket in, but maybe someone can forward this to the WoW forums, considering i can't post on those forums.
Thank you.
While in DA, it uses Twilight Ward still, and doesn't make the change into a Fury Ward.