Project X Zone is one of those games that many thought would never be brought over to international audiences. As a crossover between three major Japanese publishers with quite a few obscure franchises alongside the big ones, trying to bring this game overseas must have been difficult. According to Matt Hawkins of Siliconera, who got to play a demo of the game, it was.
Speaking to a representative of Namco Bandai, it was indeed difficult to make sure the international version of Project X Zone retained the same characters. In fact, the rights to every character in the game had to be re-negotiated, even for small characters like John McClain from the arcade version of Die Hard (though, he’s not called that here). Nevertheless, all thirty characters from the Japanese version of the game will be available in the international release.
You can read more of Matt Hawking’s impressions of Project X Zone here.