Seriously, XIV will drop PS3 support when the PS5 gets closer... and that's probably not too far off.

It wouldn't make sense to develop for three generations of the same console, especially considering the price of the PS4 will plummet as the PS5 draws closer. And Yoshi-P said before the launch of ARR that he'd like for XIV to be a game that stays current with technology. He has also been refreshingly non-committal about holding onto the PS3 in the long run.