I was looking more closely at those screenshots in the Konami site (which unfortunately are the same in every region, even Japan) and I do believe they show us costumes!
Nothing special, of course, but they do look like they might be a little bit better than the terribly generic Bomberman Live costumes, and either customizable or tailored to each character.
Oh, also, did anyone else notice you seem to fight Brain Bomber on a movie studio?
Yellow Bomber seems to be on the same platform as the camera, there are those suspicious tiles, and the camera closest to him seems to be about to hit by a laser beam, so maybe it is the boss gimmick.