From Earth's frame of reference it's effectively instantaneous but if the Sun suddenly disappeared then Earth's orbit wouldn't change for 8 minutes. It would appear to be pulled to the point the Sun would have been in 8 minutes had it not disappeared. Is that incorrect?
No, you are correct, and I think you are really getting to the heart of what the difference is between the speed at which gravity propagates and the speed at which gravity waves propagate. Your example would be an example of gravity waves propagating, and not gravity propagating, which is why it would act at the speed of light.
It helps if you stop thinking about gravity itself and think about it as an effect of the geometry of spacetime. Mass warps spacetime, and gravity is the effect we feel as we travel through warped spacetime. Once the spacetime is warped, we feel these effects instantaneously, because they are produced by the geometry of the local spacetime we are traveling through, like the slope of the road you are driving your car over.
Now, if the sun were to disappear, spacetime would “unwarp”. That “unwarping” could not happen instantaneously. THAT is what would propagate at the speed of light, the “unwarping” of spacetime. Gravity, being an aftereffect of the local geometry of spacetime, is always going to be instantaneous, but the changes in that geometry can’t happen instantaneously.