Did you read the article?
The point is that the story of the Revelation could not have been introduced later without being exposed as a fraud.
Moses lived about 1500 BC. As far back as 800 BC, neither Israel nor Judah was truly monotheistic. About 600 BC, monotheism ascended and subsidiary cult centers were wiped out. Soon after, the book of Deuteronomy was rediscovered in the Temple of Judah.
I'm not sure how this follows. So let's sum up the argument... The ruler Josiah supported monotheism, suppressed opposition, and the religious center in Jerusalem put it's weight behind a holy book. In the holy book was a story almost 1000 years old that talks about a divine revelation to all the Jewish people. This story didn't destroy the rulers and powerful people so therefor the story must be true.
That's a weak and pitiful argument and does not constitute absolute verifiability.