As @FPizz pointed out. It's all over-valued and over-developed garbage land that is at risk. Cape May may be a rare exception but yeah. The only people who stand to lose much are the super wealthy. However the loss of mangroves and wetlands will entail an extinction threat for some species of birds and fish.
The way we live is completely wrong. Coastlines are the most valuable assets you could ever maintain because they protect you from oceanic pollution/overfishing and storm surge. Most coastlines should be human exclusion zones period. Only allowed for aesthetic and rewilding reasons.