There may not have been a “real” Atlantis, but surely there are many myths that may overlap with the absolutely certain story of Thera.
We have one (just one) account of an eruption on Thera, and the dating of that eruption works out to about 200 BC. Herodotus writes quite a bit about the island, and doesn't mention it -- but he lived before that eruption, so no surprise there. And Plato was earlier than Herodotus.