Ignoring the 10k-20k years part, which I agree it's a little iffy, by definition the first languages of North America originated in Siberia and in the present

Ignoring the 10k-20k years part, which I agree it's a little iffy, by definition the first languages of North America originated in Siberia and in the present Russian Far-East, for the simple reason that there's from where the first populations of North Americans came from (I think that the Trans-Pacific theory is not widely accepted). Unless those populations only started using language once they had set foot in North America, which would be an even greater thing to push.