Actually, new discoveries are being made frequently enough now that some of the older accepted dates are being discarded.
For example, we now know that much of the Persian Gulf was dry land 10,000 years ago. As the great ice sheets melted and sea levels world-wide rose, areas previously inhabited became flooded and peoples migrated inland. Some of those previously inhabited but now flooded abodes have been found, on the sea floor between England and France, and stone cities 35 km off the southern coasts of India.
Since the ice sheets actually began melting 15,000 years ago, this puts the beginnings of human civilization back quite a few millenia!
And won't it be a kicker when they find out a major point of origin was the Amazon basin.
By any chance did you read Graham Hancock’s book “Underworld”? He addresses the inundation of very early civilization coastal sites at the end of the last great ice age.