I've got it! SE will port DDD HD alongside XII HD! Bwahahaha! ~ or bundled with FFVII PS4...
*ahem* but what if they just made the ReMixes available on PSN and they wouldn't have to re-release it? They would have to make it digitally available anyways if they release it for ps4.
I'm not sure what you mean by PSN. PSNow? Or PSN in general because keep in mind PS3 titles are not compatible on PS4 systems except on PSNow and that service is terrible.
They can't put it on PSN and just go "okay play!" it would have to be ported to PS4 to be playable. This is the point. People playing it on last gen have no issues accessing the game. Putting it on PSN does nothing.