I don't have any insider info, but it's better to view this as the latest attempt to push churners to business cards. I've been seeing better sign up offers for the biz cards for a while.

Meanwhile they are clearly pulling back from the heavy marketing on the personal cards (the new Everyday card being the obvious exception).

I won't cry for American Express, the company is very profitable and growing, but on the high end they are obviously getting pinched by Chase and now Citi too. The AmEx product line has become messy, and is in need of trimming. Maybe this is their first step, because they clearly need some new blood in product planning.