Re the legal stuff. There is precious little you can do by just changing you name in the manner that happened here, you can resell your brand, drop out of a franchise and a few other things besides that will force a name change. Unless you also declare bankruptcy or something really fun like vanish/quick sell your assets then most legal systems are smart enough to see through it.
This is far more likely because some analyst of theirs said the Bandai brand had more resonance or something with the public, because it provided a more unified front to advertise from or some such. If their analyst was especially cretin class, or stepped out of an 80's time warp I guess, then it might have also been because B is higher up in the alphabet than N (ever wondered why so many tech companies start with an a?).