I have never found evidence of interpretations of these legends, but there are abnormals that luminesce. It may well be that what doesn't exist in one timeline can exist in another. While not directly tied to fireflies, some stories of the kitsune say it is able to produce fire or lightning, called fox fire. And kitsune can be called fox spirits. Some even take companions or hosts and protect them or give them gifts.
What information do you have that you are connecting these legends to?