The references cited seem to want to view the entanglement from inside the event horizon. It is as far as we know a oneway trip which no one would want to take UNLESS we first obtained some inkling or theoretical insight that we could obtain state information from the photon inside the event horizon communicated to the photon outside the event horizon.
As far as I know entangled particles cannot transmit information to each other. This would mean that they cannot do so if one is inside an event horizon and the other is not.