I believe that matter is captive energy, and its gravity is the gravity of that energy. Gravity propagates much faster than light, but you can't make matter instantly disappear without converting it to another form of energy.

Suppose some process could instantly convert the Sun's mass into a uniform spherical shell of electromagnetic energy, expanding at the speed of light. At any point outside that expanding shell, the gravity of the shell's energy would be exactly equal to what had been the gravity of the Sun's mass. At any point inside the shell, the net gravity due to the shell's energy would be zero (as explained by Newton's shell theorem). So the planets would continue to orbit as before until the instant the shell of light passed them. Eight minutes after the sun's mass suddenly became light, Earth would be hit by a terrible flash of light; then the sky would go completely dark (except for other stars), and the sun's gravity would disappear at that instant.

If anyone on the night side of Earth survived the cataclysm, they would see the outer planets still in their original orbits until, one by one, they are illuminated by the shell of light. As the shell of light passes each planet, it shines blindingly for a few seconds before going dark. The planet then stops accelerating toward where the Sun had been and goes off on a tangent.

So there would be an eight-minute delay before Earth would stop feeling the Sun's gravity, but that is not evidence of gravity propagating at the speed of light. If gravity did propagate at the speed of light, the Sun's gravity would pull us in the direction where we see the Sun, not the direction where the Sun is. Therefor, we would be pulled forward into a higher and higher orbit and eventually ejected from the solar system. The very existence of solar systems is proof that gravity propagates many times faster than light. Tom Van Flandern calculated that gravity has to be at least twenty billion times faster than light to explain the lack of forward acceleration of planets. While I poo poo some of his wild theories, I believe he was right about the speed of gravity.

If instead of a uniform spherical shell of light, the Sun were converted to a pair of equal and opposite photon torpedoes, the shell theorem would not be applicable. At distances many times the light travel distance since the event, the gravity would be equal to that of the Sun's mass at the center between the two photon torpedoes. But as the angular size of the separation between the photon torpedoes, becomes significant, the gravity would have to be calculated by some formula which I don't know. I leave that to the mathematicians. I suspect an observer would be strongly attracted to a photon torpedo passing near him, while the other one would have negligible effect. The gravity would gradually increase until the photon torpedo passes the observer, and then it would gradually diminish. The observer would not see the photon torpedo unless and until it hits him; light is not an emitter of light, but I believe it does have a gravitational field.

Note: Newton's shell theorem tacitly assumes that gravity propagates at infinite speed. Otherwise, there would have to be a light-speed delay factor in the proof of the theorem. The absence of such a factor has no effect as long as the shells are static. If the shells expand or contract, a speed of gravity factor would be needed to prove the validity of the theorem.