The fact there are outliers doesn't mean a blanket statement is "racist" as long as it's accurate for the most. It's doubly not racist if it's positive (and "understanding how the world really works" is a positive thing).
Given that blanket statements such as that, which are meant to imply "in general", are indistinguishable from actually bigoted blanket statements which are meant to be taken literally, it probably is a good discipline to always include "generally" or "typically" as a qualifier, each and every time. It has fallen out of fashion, but let's try to bring it back.
Context matters: in a discussion of percentages of a population holding particular views, where it is offered to explain why a certain percentage of blacks holding a view is improbable, that's not a blanket statement, its a statement about the relative frequency of experiences relevant to the belief in question.
Class isn't immediately visible. Skin is.
You mean just like a racist society does (which makes the statement even more accurate)?
Because even a "rich/european/etc" black person is still a n... when it comes to a racist society, and while his experiences might be better, they'd still be shaped by racism.