The new dev teams artwork is throwaway too then (There's no such thing as throwaway concept art, concept art is usually used for ideas and modified upon throughout, not thrown out). Also if you actually played FF games, especially the early ones, you'd know Amano's art work for FF games doesn't always have an overall meaning to the image but more of an image of either people/places from that game that may be designed to symbolize certain aspects. So there's no "meaning" behind it as of the past 1.0, there could have been further meaning if 1.0 was fully developed by release instead of rushed out.
Example:
XI's Zilart Artwork:
Looking at this image you'd say: "OMG CHOCOBO KNIGHTS!" if you're trying to look for an actual meaning.
FFV's Artwork:
Note the lack of Gilgamesh or Exdeath?
There's no real "meaning" to a lot of his art for the games depending on which ones you look at, but cover art/early images are just concept designs.