Interesting! As with most science, the new information only raises more questions.

The Endangered Languages link says Siberian Yup'ik is closely-enough related to Alaskan to be cross-understood, yet it completely ignores the Alaskan side (linguistically, not geographically, as apparently the Siberian dialect is spoken in the far reaches of Alaska, such as Savoonga and St. Lawrence Island) in declaring the language nearly dead. Yet, it certainly didn't seem close to dead when I was there.

I built and managed the first radio station in the Bristol Bay region (KDLG, in Dillingham), and one of the first things we did was incorporate Yup'ik programming: a man who told folkloric stories in Yup'ik.

KYUK, a station in Bethel, 100 miles or so to the west, also had regular Yup'ik programming. In fact, the call letters signify the Yup'ik word for "People" or "Nation": "Yuk" (which is also the root for the name of the river Yukon).

Granted, it has now been a long time since I've been to the region, and maybe things have changed. Maybe Yup'ik is no longer taught in the schools, maybe books are no longer being translated and written, and if so that would be a sad pivot from the direction things were going when I was there.

Probably a good resource for the language development would be the University of Alaska, Fairbanks, but, unfortunately, the one link I saw to UAF was a 404.