Not necessarily. The biblical flood and a majority of flood myths around the world, go back much farther than that. Many seem to have been inspired by events during the Younger Dryas period, around 12,000 years ago. There's a "black mat" layer in soil all over the world, suspected to be the result of some sort of cosmic impact - a comet or asteroid hit North American ice, resulting in cataclysmic flooding and a radical reshaping of the geology. The fires from the resulting storms pumped so much ash into the sky that we now have a visually distinctive indicator. Anything above the black mat layer is younger than 12,000 years.
North American megafauna disappeared at this time, which is a pretty serious crack in the assertion that overhunting by people caused their extinction.
Storms from this event left evidence of massive flooding in the years following the impact all over the world. I have no doubt that there are cultural myths that stem from not recent flood events but the younger Dryas impact is likely the source for the oldest myths, as the destruction seemed to be so profound that it would have wiped out any coastal settlements all over the world, leaving us with evidence of the survivors and nothing of what they lost. Various sites and clues around the world hint that even 12,000 years ago there may have been relatively advanced cultures that built in stone and wood, planted crops, likely had advanced shipbuilding, math, astronomy, and navigation.
There are petroglyphs at sites all over the world resembling stick figure men that seem to be inspired by massive plasma discharge patterns in the sky, and the Younger Dryas impact hypothesis provides an explanation for storms powerful enough to produce such patterns.
https://www.pnas.org/doi/10.1073/pnas.0800560105
https://en.wikipedia.org/wiki/Younger_Dryas_impact_hypothesi...