Tom,
The FPC limits the interpretation of the equivalence principle to the exterior and ultimately the boundary of the BH. The orthodox interpretation allows a dual existence, at least temporarily, for a test particle that "falls into" the BH. For exterior observers, the test particle ends up and remains at the boundary until the end of the universe. From the test particles' frame of reference, it passes the event horizon and continues falling ultimately ending in an unknown state at the singularity. This is a paradox! The FPC removes the paradox, since the particle's very existence is defined only w.r.t. the rest of universe, which is the exterior of the BH and its boundary. This doesn't negate the equivalence principle, since at the boundary, the test particle remains in a locally timeless state and experiences nothing, that is until it's energy is eventually liberated by a extremely long period of cosmic expansion. Without the FPC, we have dual existence and unknown states. With the FPC, everything has a unique existence and the singularity is understood as just a point in cosmic time. The remains of the star interior to and immediately after the horizon is formed, exists in a new set of expanding spacetimes, with the BH's event horizon equivalent to the cosmic horizon in their infinite future.
Dan