The anarchist's being anti-oppression is only a corollary of a "higher maxim". The anarchist is anti-oppression *because* he values immediated social relations of unique ones, etc. He simply is not a slave-moralist nay-sayer to oppression, but a master-moralist who affirms life and creates values, and anyone who oppresses it is his enemy. So to answer your question, anarchism is not just anti-oppression; it's pro-ego, pro-nothingness*, pro-immediation, pro-authenticity.
*I know this is a vague term, so lemme just clear that by "nothingness", I mean the spontaneity of the ego and hence the lack of essence.
