This was planned all along.
The GT Advanced plant was just used to develop the expertise and do all the trial and error tests. Once all the kinks were worked out, they arranged to tear down the whole operation and set it up at Foxconn where everything could be done much cheaper and integrated into the assembly process already in place.
The feigned surprise at Apple that GT was going bankrupt was a dead giveaway.
Conspiracy theories are always so much more fun than the truth.