I know this may not necessarily be the case here but and i cant remember the exact example but one of the proto engine management systems i used to work with was recalled and redesigned and it came back bigger.

They said that it grew because although the all of the components were the same, the board was redesigned to allow for a more logical signal flow and this actually improved the performance of the device.

This may be completely irrelivent but it this example just came to mind when i read this thread. Only speculating but perhaps something simular is being implamented to maybe reduce noise between components and increase efficency.