Interesting, very much worth pursuing further the treatment of difference "outside terms of oppression." Its a general problem, and one for which there are useful examples, and perhaps a coherent general logic. See Diversity and Deviance: A Biological Perspective for some of my own early wrestling with this and the second to the last paragraph of The Brain and Social Well-Being, Followup for some current realizations of the breadth of the terrain.

The point is that biological evolution and biological systems, including the brain (see From Disciplinarity Through Brains to Cultures, and links from and forum comments there), provide instructive examples of the successful and productive interaction of diverse entities without "oppression" being an issue. These would be worth exploring in the "social justice" context.

What all these things suggest is that "to come into relationship" does in fact "get somewhere outside of this" (see The "objectivity"/"subjectivity" spectrum and If there can be no single definitive description of reality, nor of beauty, nor of virtue ..., and links from and forum comments there). Where it gets is a place in which 'relationship" extends the inquiry/exploratory capabilities of the interrelated.