Could it be as simple as:
XB1 SDK AF On Default
PS4 SDK SF Off Default
Some Devs Change it others leave to default?
Judging by the state of games launching this gen, Devs have far more to worry about than changing a default option.
Seriously? You really think devs are so bad that they would do that? People here make it sound like devs don't even know what AF is... AF has been around forever and is pretty much just a matter of adding an enumeration value somewhere in the code. Hell we used it extensively on PS3 ourselves...
So if a game does not have AF everywhere it just means that it was part of a decision made by the devs somewhere along production and that's it. People should stop trying to find some reason seemingly only to fuel the console war (at least that's what it looks like in my opinion).