These are previews of the Tails for the VN. Technically, the image did not change between now and the original release. What has changed (or been added to most cases) is their nicknames. While I not going to tell you their birth names, I will tell you their nicknames:
Cross (Zooey's kid)

Zooey's son is a pure fox. Giving him two tails won't make a difference since all the other kids have two tails (and in most cases, take the mother species). So, I'm going to do something different for his tails.