Yes and no
Atlanta was and still is a transient city.
However Atlanta uniquely has decades worth of black history and culture that no city On the west coast can compete with.
If you really think about, the west coast ( I love the west coast and the people ) doesn't have enough black folks to really cultivate black culture that's exclusive.
If you credit the west coast for these things you ultimately have credits other ethnicities and cultures as well.
I say this with respect to both the west coast and Atlanta.
The correct answer is black people not a region. Lol