If amex had a problem with their names theyd have many more problems than just that, like B and H had.
Not Legal problems. I'm talking about lost business kind of problems, or just making things more difficult.
I picked B&H as an example. There are plenty of other people and companies that try to Americanize their names. Is this just stupid of AMEX, or maybe they realize it's not needed (and we should follow too).