I wouldn't read too much into that. I'd love to work on it but I'm fairly low down on the information chain so I don't know much about the situaion with Persona 4.
Ghostlight's Ross on his twitter account mentioned that he 'hopes' to see Ghostlight bring Persona 4: The Golden on Vita.
Make of it what you will, But I do think we will see the game come out here especially with the lack of an RPG on the western launch lineup for the system.
Japan already have three RPG games for Vita on sale; Ragnarok Odyessy, Lord of Apocalypse and Disgaea 3.