So after talking with some other gladiators and playing around with it, it's obvious that you can't parry while wearing a shield in this new patch. Even with foresight 2 up, it just doesn't happen. The instant you take off your shield parrying works just fine.

So, is this intentional? It seems like a bug. There's +parry materia that can go on gladiator weapons and it'd be completely wasted (on a sword) if this was an intended change.