Frankly, this puzzles me. A new discovery that at least doubles and perhaps triples the timeline for humans in the western hemisphere.
I don’t know how such a date fits with the theory of a migration from asia during the Ice Age which exposed a land bridge from Asia to Alaska.
The whole concept might have to be re-thought.
It is. Think boats.
There is nothing whatsoever incompatible between ancient peoples migrating across the Bering Strait during the last Ice Age, and migrations in earlier times. Simply because modes of travel would have been primitive does not mean travel was impossible, either on foot or by primitive rafts or boats. It doesn't take much to make a large, if crude raft.
Even today, the Bering Strait is only about 58 miles wide, and the two Diomede Islands are almost exactly in the center of the strait. It's about 27 miles of open water from Siberia to Big Diomede Island, about 2 miles from there to Little Diomede Island, and then about 27 miles to Alaksa.
Homo sapiens has always been a migratory species, despite the rise of the nation-state (Egypt) and the concept of borders about 5000 years ago.