It’s like the joke, where the man goes up to God, and says, “We don’t need you anymore....we can create life, just like you did.” God says, “Ok, show me.” Then the man says, “Ok, let me start by getting some dirt.” God immediately cuts him off and says, “No...no....no....go make your own dirt.”
Of course the universe is capable of creating itself out of nothing. Especially if nothing is not quite the condition before creation.
Does the so called law of gravity precede creation? If so it is immutable. The only general understanding we have of God is His immutability. Is he calling God gravity? Or is gravity merely the single facet of God Hawking is capable of acknowledging?