From the photos, I’ve wondered how much of that land will ever be recovered from the sea.
Large swaths of land probably won't be recovered as it was farmland and not commercially "high value" property such as that in Tokyo Bay. But measures to protect the remaining infrastructure (roads, rail, bridges, tunnels) that is reasonably recoverable will likely be made. Some may have to be relocated and rebuilt from scratch, to the extent those rural areas are re-populated by remaining/returning residents.
Some towns and villages may simply be gone for good. IMHO