My first playthrough of Dawnguard was slightly rushed, so I could have missed some lore. Did anyone find anything to do with Meridia in Dawnguard?

A few months before Dawnguard was released, I recall seeing some energy going into discussion of Meridia, her relationship with Magnus (his daughter?), and with the wandering star Mnemoli and the "illicit spectra", and as I recall, MK made an appearance in that discussion. This was followed by MK publishing several short pieces describing other planets.

When Dawnguard was announced, I wondered if there was a connection; if the developers and especially MK were dropping hints about the lore content of the expansion. The plot of Dawnguard concerns the plot of a vampire lord to blot out the Sun. Meridia is associated with light, associated with the Sun through Magnus, and hates the undead. So, I was expecting this to come up, somehow, in the plot of Dawnguard. But I don't recall anything mentioned about Meridia, Magnus, or the more esoteric beings.

Instead, there's Auri-El, and Auri-El's bow, which I really didn't expect. Why Auri-El? For that matter, why Snow Elves?