The latest issue of Weekly Jump reconfirms Squall Leonhart (voiced by Hideo Ishikawa) and reveals Quistis Trepe (voiced by Miyuki Sawashiro) from Final Fantasy VIII will appear in World of Final Fantasy.
The magazine also reveals that the headquarters of SeeD, a military force from Final Fantasy VIII, will appear in the game.
Additionally, a new character named Chocolatte (voiced by Seiko Ueda) will appear. She is similar to Final Fantasy XIII-2‘s Chocolina in that she wears a chocobo outfit appears in unexpected places selling items.
World of Final Fantasy is due out for PlayStation 4 and PS Vita in 2016.
Thanks, @kazu4281.