According to a Reddit report, a number of people recently had all of their AMEX credit cards shut down, likely because they applied using a 150,000-point AMEX Business Platinum offer that was not intended for them. What these people had in common is that they all received the offer via chat from an AMEX representative named “adam.” That offer was apparently a targeted offer with no lifetime restriction, meaning even people who had previously held the Biz Platinum could still receive the bonus. Interestingly, some people who were applying for this card for the first time were also shut down in the end. It seems AMEX may have simply gone after everyone who used this offer in one sweep.
In any case, if you also used this offer, it may be safer to prepare to transfer out your points. If not, it’s probably best to avoid using this type of targeted offer for now.