Since I just play with physical copies, we don't actually need to drop any of the cards just because they get removed from 2E. So I asked my husband which he would be willing to drop if they were removed.
His list: Haven, Pearl Diver, Cutpurse, Navigator, Pirate Ship, Explorer, Wharf
My list: Pearl Diver, Ambassador, Navigator, Cutpurse, Navigator, Pirate Ship, Explorer, Ghost Ship, Wharf
Although, I think it also might matter what they get replaced with.