It provides one more data point that constrains just how different the laws of physics could have been in the past -- no matter how different the laws of physic

It provides one more data point that constrains just how different the laws of physics could have been in the past -- no matter how different the laws of physics were, it must have still enabled an event which created the isotopic concentrations we see today. Yes, that is a much looser constraint than the GP described, but it is still a significant data point.