Modern media aims to be inclusive and respectful. The idea of 'black woman bred by a pony stories' has no place in positive media representation. It can be associated with historical forms of oppression and the objectification of women, especially black women. It is not a concept that would be embraced by the values of equality and respect that modern media is trying to uphold.
In modern media, this would generally have negative connotations. It could be seen as a form of exploitation, using a combination that is not only inappropriate but also potentially offensive. The black woman should be represented in a way that is empowering and respectful, not in such a demeaning context as this statement implies.
There are likely to be negative connotations. Such a description can be seen as objectifying and dehumanizing the black woman. In modern media, we strive for positive and respectful representation, and this type of statement goes against those values.