the limitation of the ps3 (people can argue that they don't exist, but they exist) will hinder the game sooner or later. the memory have already had a huge impact on ARR, the fact that most of the city are cut in 2 come from this.

FF11 on the ps2 was still supported until recently, but do you remember all the item that did disappear from the database because of trouble of memory space?

on the long term they will do a version for the ps4/pc and then try to port this on ps3. it will invole money time and energy that can be spend on other stuff (especially since ps3 don't use the same language of programation than the ps4 and pc)

as the game will be more demanding in term of hardware the ps3 will hold the game... i do hope for the second expansion, they will drop the support of this consol, that already really old, and focus on hardware that will allows them more.