And what Hayek was saying was that it was very murky indeed even back in 1977 how exactly social justice was defined
Hayek presumably is fighting a rearguard action against any attempt to include redistribution under the label of “justice”.
Of course, there’s always a risk if you include redistribution in justice and then get carried away with it or apply it selectively, so I’m mostly opposed to collective intergenerational justice in anything more than weak forms.