Exactly what I came here to ask. Is Hawking's theory that the area never decreases or that it does not decrease in a black hole merger as was tested here. "central law for black holes predicts that the area of their event horizons — the boundary beyond which nothing can ever escape — should never shrink" this seems to imply the former to me.

Does that mean with Hawking radiation the black hole effectively evaporates by loosing mass (?) from the inside without the boundary area never shrinking?