I really don't see how it will be too difficult to localise. From what I saw, all the IPs used are wholly owned by Namco, Capcom and Sega, all of whom have prominent western establishments. So as long as all of them are okay with their IPs being used in west for this game (which I don't see why they wouldn't be), Namco can just go ahead and publish it over here. Plus I think all the characters featured in this game have had western releases through their respective titles.
So yeah, hopefully we'll see it here. This is nothing like the Jump Ultimate Stars game where the publisher didn't actually own the rights to the characters used in the game, and hence it would have been too complicated to localise in the west given a lot of those characters were unrecognised in the west.
