There is some discussion of the new terms in this thread about a similar offer:
http://www.flyertalk.com/forum/ameri...6-26-12-a.html
The literal reading to the terms would mean that you would not be eligible to earn a bonus on a business green, gold or platinum card until 12 months after you cancel your current business gold, but some CSR's have indicated that it only means that you cannot have opened a new business charge card account within the past year.
The business credit card should be irrelevant.