Actually, it doesn't...by a longshot. The historical dating of pre and post-Noah era has been pretty well established with some certainty. The flood of Genesis dates back to 2300 BC...*after* the pyramids of Giza were built. Think about that.
This city, if it was 6,000 yrs old, would be 1,700 yrs older than the flood.
From the same National Geographic Article...
"Last year, Ballard and his colleagues found proof that a catastrophic flood inundated the Black Sea in the region north of Turkey. The place and date of the flood—which may have occurred around 5,500 B.C.—correspond to the time and location of the Old Testament account of Noah."
It appears the dating of "Noah's Flood" is in dispute. Of course there may have been more than one great flood.