If you're going to go by a Gran Turismo argument, remember that GT5: Prologue was indeed released on the PS3 and shipped over 5 million according to PD.
That was all for a tiny, tiny amount of content. They really did well for themselves there.
I think a GT6 launch with the PS4 would be a very smart move. They've already had a few years working on it, polish polish polish.








