That doesn’t match the archaeology. They’ve recovered all kinds of artifacts from Akrotiri. The ceramic styles, for example, can be keyed to specific periods and those styles are far older than 200 BC. They’ve also radiocarbon dated plenty of organic material, including an olive tree buried alive in volcanic ash, and those dates got back to 1600 BCE.
Nope. RC results are skewed on the island, such that living plants growing in the “dead carbon” rich soil test out 1000 years old and other flakey stuff. There’s no reason to believe it hasn’t been that way for as long as the island has had soil, since it was formed by a volcano.