It’s a shame, but PS Vita is dead for the majority of video game developers, (even for the Japanese ones). Many games that grew on the handheld system must now find a new and healthy ecosystem. God Eater is one of those IP, and PS4 could be its new home.
God Eater 3 appears listed only for PlayStation 4 on a post on the Bandai Namco Entertainment Korea official blog. However, we must be cautious with this info, since this same blog list Dragon Ball FighterZ only as a PS4 title and it will be also be released on Xbox One and PC.