Ooooh, two Madame X's! I like that theory.
The GDB does seem more important than meets the eye to everyone, Bladestar, Team Xen, and the Interceptor's merry band of heroes. We know that the GDB led to Melia, Erin, Alice, and Allen all gathering at the Shrine of Rejuvenation. We also know that they can somehow form the Archetype which somehow relates to Nymeria/Indriad and holds immense power. I feel like the ball was "fated" to reveal some sort of power that they share and begin to fit the pieces of Melia, the Archetype, Team Xen, Erin, the Garufa, and Anathea together.