Console has nothing to do with integrating mods. If there was a process to integrate third party mods, that would include Squenix:

1. Ensuring the mod does not change the technical requirements (Given the fact that the low end PC players are the ones that are really "holding back" the game, not PS4)
2. Ensuring the mod does not conflict with any in-game systems (Both current and future)
3. Ensuring the mod does not allow for an unfair advantage compared to other players
4. Ensuring the mod does not contain things that change the ESRB/PEGI rating of the game
5. Ensuring the mod itself does not have any major bugs
6. Ensuring the mod doesn't conflict with any other mod
7. Figure out ownership/IP of the mod


These checks need to happen with every update of every mod every time either the mod or the game makes changes.

The reason why they aren't going to integrate mods into the game is that in order to "do it right", it would be more work than making the changes themselves. It adds way too many variables to a huge game that already has way too many variables.