Alignment is hard baked into the "standard setting", the 17 Outer Planes of the Great Wheel and the worlds in the Material Plane contained therein. As long as D&Ds flagship srttings is one of these worlds (as it is with the 5e Forgotten Realms right now), alignment isn't really going away. There are other signs of how intertwined alignment is into the setting but less so the system, but the default planar cosmology is the big one.