That article links to a 9to5Mac article as its source. That 9to5Mac article doesn't mention anything about AMD GPUs.
I would lend more trust to The Verge and ABC's tech news department on this:
It could happen as a last minute change, but that isn't very likely.
This. Well put.
I'd also like to add the article is just a contradiction of itself. AMD's Trinity is a processor/GPU combo chip, not a code name for a discrete GPU, even though halfway in the paragraph they claim that new MacBooks are expected with Ivy Bridge processors? According to that site, the new MacBooks are going to have both AMD and Intel processors onboard? I'd stop reading that site to be honest.