Board Thread:Lore Discussion/@comment-8248675-20130901184023/@comment-3076045-20140318011136

They said pretty early on that they are related. Tharn Family has some more information. (although it needs some updating with more of the information learnt from beta, and soon, the game itself).

And no, its not an easter egg. It's meant to signify that this is how they came to power, and their evil intentions generally. In the same manner that Mannimarco was evil (and actually worshipped different Daedra at different periods in history).