If the R&D is done, the manufacturing process has been taken care of and they mated this 6 speed auto to the 2.4L ecotec and are willing to put it into the new Malibu it would make sense, in my mind, to offer it as an option on as many vehicle as possible in order to get the money back from the development process.

Not only that, but by offering a 6 speed auto on vehicles like the HHR and cobalt and other vehicles GM can set themselves up to compete with other vehicles that already have that sort of tranny and even become leaders amongst those cars that don't offer a 6 speed option. By putting forth the idea of wanting to lead and build superior cars it could and should increase sales (that is unless too much damage by previous management decisions hasn't already been done that can't be repaired.)