I have no issue with a girl stating that she only sees black guys, in fact, being white, I am kind of glad to see it. All SP girls have a right to their personal choice regarding who they get intimate with, I do not see this as racist (although I accept in some cases it may be born from that).
There are plenty of girls who won't see black guys, strangely, early in my punting career, two young, fit, white girls I (separately) questioned about this, (at the end of a meet), both had boyfriends who were black. The first said, black men were her type so she didn't want the potential confusion of falling for a punter. The second intimated that it was her boyfriend who didn't like her seeing black men. Of course, it's a sweeping generalisation but we also know some girls are concerned about "dimensions". So I like to believe that mostly it's not racist, without denying that some of it might be.