I just read this, from this article in the news section: https://www.elderscrollsonline.com/en-us/news/post/55055
"Q: I've heard you're rather knowledgeable regarding the Murkmire region of Black Marsh, so I'd like to know where the Lilmothiit are! Or, at least, if there's anything leftover since they supposedly lived in that region? - Ta’asi
"A: Ah, the answer to your question is sad-sad! Our vulpine neighbors the Lilmothiit had been in decline for many of their generations, the closest clans having withdrawn from the coastal areas inland toward the city of Blackrose, just north of Murkmire. Alas, the Knahaten Flu, so dreadful for dryskins, struck the Fox-Folk with near-total lethality. No one I’ve spoken to in Murkmire has seen a living Lilmothiit for many swims."
Near-total lethality, not total lethality. Migrated north of Murkmire.
It seems to be a clue to a future DLC where we might see a living Lilmothiit (maybe). The phrase "near-total" is the most interesting part of that, in my mind.