I created this thread so that we can speculate on how BGS will address this fact, from both a gaming and a lore perspective.
Personally, I suspect that they will create 5 new constellations, but I'm not sure how that will be explainable in the lore. Will these new constellations be birthsigns? If they are, how will this affect the traditional view of associating the birthsigns with the months in a year? If these constellations only recently appeared, what impact could this have on the world of Nirn?