That actually is really cool. That implies a certain degree of isolation for A very long time. Do genetics in that area have any interesting patterns?
The Ket language of central Siberia has long been believed to be isolate, but was later classified as a member of the Dene–Yeniseian language family (or at least proposed, afaik this research is still ongoing).
Wild to think about.
This find is about a script in an unknown language.
The question about how old spoken languages are is of course unrelated and can't be answered since it predates history ;-)