If an archer uses the point of the arrow to gap and they get lighter arrows or a faster bow, this would change their gaps, so all they do is learn the new gapping system, is that correct?
I think you are right.
The gap that you are talking about equates to the gap between the arrow and the sight aperture for an archer who uses a sight. The sight is on the gold and the arrow is usually below. The further you shoot the smaller the gap, as the arrow is raised to make the distance. If the sighted archer wound up their draw weight and the arrows landed high they would raise the sight to compensate; effectively lowering their arrow or increasing the gap. The sighted archer gets used to knowing how much to move their sight to bring the arrows to the gold when they land high or low during sighters, for example. The gap shooting barebow archer may learn to use a bigger/smaller gap for the same reason.