Hmm. This all seems to be an extension, if you will, of Ryan and Pitman's book
Noah's Flood: The New Scientific Discoveries about the Event That Changed History. I read it several years ago - pretty plausible-sounding stuff. Not "hushed up" at all, either: it was a best-seller and National Geographic, I think it was, did an article and TV show on it. And the authors are oceanographer types.
Though I have seen, somewhere, contrary opinions about the filling-up of the Black Sea.
As to your question: I'd be astonished if big floods weren't recorded in mythology. I'd be more astonished by far if anyone could come up with a scrap of evidence for a truly global flood in the last half-billion years or so. But yes, if the Black Sea filled up like Ryan & Pittman postulate, the folks there would have thought "the whole world's drowning!"