I'm not seeing that behavior. When I change skins, the point attachment is gone. Can you post a project showing the problem?
You can always grab a point attachment at runtime, from whichever skin it is in. You can also call PointAttachment computeWorldPosition and PointAttachment computeWorldRotation at any time, even if the point attachment is not visible. However, it is most common to get the point attachment from the skeleton's current skin placeholder using Skeleton getAttachment. That way if the skin changes, the point you get changes. For example:
PointAttachment point = skeleton.getAttachment("slotName", "skinPlaceholderName");
vec2 position = point.computeWorldPosition(bone);
float rotation = point.computeWorldRotation(bone);
