If much of ice age human settlement was along coasts (as it is today) we would expect many if not most possible evidence of human settlement to be submerged. This could mean that we are underestimating the scale of human habitation of various regions. I'm curious what an archeologist would make of this idea.
Interestingly, there is little change near the southern tip of Florida, which might explain the locations of the findings in TFA.
As you can seeon the map, huge areas were dry land then but are ocean today. On a global scale, these include the entire Hudson Bay, and all the sea between the UK and Western/Northern Europe.
So I guess your theory isn't controversial at all.
Graham Hancock has an interesting theory of a worldwide civilization that was wiped out (along with the mastodon) by a comet hitting the north american icecap during the younger dryas period around 11000 years ago.
Why does this read like Chrono Trigger fanfiction? That is almost literally the entire Zeal subplot from that game, except the meteor wiped out the dinosaurs, and the Queen of Zeal destroyed her empire 12,000 years ago through greed and stupidity DUE to the meteor.
I've always thought it interesting that the Natives of the new world were basically living a Stone Age existence. For 15,000 years, it turns out.
Aside from outlier examples to the contrary, there was basically nothing around for the European settlers to discover but basic tribesmen, oral history and primitive notions of things like weather, cosmology, medicine, etc.
