No way it will have a 7870 or close, more likely a low end card that can crossfire with the APU, where did you get the leaked spec from?
These are the interpretations from PSX sense, the european site who claimed to have the working specs for the ps4. I think that these specs make sense. and they could probably custom configure the apu to crossfire with the high end GPU, right? it is a console, and anything is possible. i do suggest that you search it up. what are your thoughts?