It's vanishingly unlikely. Here "vanishingly unlikely" has the same meaning as if it were used as an answer to a question about whether Elvis was kidnapped by Martians. It's not strictly possible to offer rigorous evidence to disprove the idea beyond any possible doubt, but it rests on such wild assumptions that it's never going to be an economical explanation of the data.
On the story's intrinsic plausibility: Plato's story involves the city-state of Athens, which had maybe 40,000 citizens at its height, winning a war in ca. 9400 BCE against a state around half the size of Brazil. For reference, the largest known civilisations in the world at that time were the size of a small village; Athens would not exist for another 8000 years; Atlantis has a Greek name and Greek gods (neither of which would exist for another 7000 years or so), magic minerals that have never been observed since, and a large population of crops and animals of all kinds including elephants.
On source criticism: there are no potential avenues for transmission (writing would not be invented for another 6000 years). Plato's story has it that Critias got the story from his grandfather, the grandfather heard it from Solon, and Solon got it from Egyptian priests. Critias was the leading figure in the regime of the Thirty Tyrants, who in 404 BCE murdered between 5% and 15% of the citizen population of Athens in order to steal their property; Solon was a famous reformer, philosopher, poet, and traveller of the early 6th century BCE. For Plato's contemporaries, this is pretty much the equivalent of a story where Hermann Göring reveals hidden knowledge that was passed down secretly through his family after it was imparted to them by Goethe 150 years earlier.
On potential real-life sources of inspiration: Plato presumably knew that floods are a thing, but no other elements of the story have any meaningful counterparts. Plato had no potential avenue for transmission that would allow him ever to have heard of Akrotiri or Pavlopetri. For that kind of inspiration, proximate motivations always have more explanatory power; on that thought, Helike and Boura, in the northern Peloponnese, destroyed by earthquake/tsunami in 373 BCE, could be an attractive candidate for a source of inspiration. But purely for the "flood" motif, not for anything else.
And on the intent of the story and its popularity: put it in its historical context. In the 370s BCE, Athens had worked hard at rebuilding the empire that it lost in the Peloponnesian War 40 years earlier, but in the 350s (when it is usually thought the Timaeus was written) Athens suffered setbacks and was forced to claw its way back to maritime power yet again. In the Timaeus, Critias uses the story to paint a picture of the ideal state, as per Socrates' requirements laid out at the start of the dialogue and following the ideas laid out in the Republic (to which the Timaeus is a sequel); so Critias is basically arguing that a militaristic Athenian empire with naval supremacy would be an ideal realisation of the Republic. The Atlantis story is a great vehicle for portraying Critias as an extremist hawk.
In later times, the reasons for the story's popularity have shifted around a lot. Pierre Vidal-Naquet's The Atlantis story: a short history of Plato's myth (2006) suggests that it became popular in the Renaissance as a kind of independent witness for the biblical Flood in Genesis. The reasons for its popularity in the 20th/21st centuries are different again.