If they want people to move with less of a battle, they need to offer incentives and compensation for the trouble. Just uprooting people is a bad strategy: a lot of wars have started over who gets to live where. They need to make sure that there are other, preferably similar in a safer place, homes that these residents can move into and enough funds to cover the cost of the move.
And then they need to look at the beach as habitat, its wildlife. Beach plants and animals are typically less mobile than humans. Can anything be done to protect what beach remains? For instance, many places used to have oyster reefs, mangrove swamps, seagrass beds, or other natural features for protection that were removed because people found them desirable and used them up or annoying and took them away. Restoring those can help. Could the beach simply be "rolled" inland as the water level changes? This would minimize the ecological damage compared to having little or no beach there.
Amazingly, here's a town in California that's doing it better. Marina keeps buildings back from the beach -- the at Fort Ord erode inland at a whopping 5 to 8 feet a year. That is "get the fuck out of the way" speed. O_O But the town is united on how to handle the challenges by shifting things away from the gnawing edge. I note that the population is substantially poor and predominantly nonwhite. I bet that helps.