Nah. Its not..... Cause what you just said doesn't dismiss anything... The fact you compared it to New Orleans and then called it a "sub culture" says it all..
How can you righteously call something "AA" culture, when its accepted by less than 3% of the AA population...
Uhh, you do understand the concept of a cultural continuum, right? As in there's not a %100 static cultural monolith even among just AAs themselves, you can break them down and isolate them even more into smaller sub groups based on factors like region as IllmaticDelta stated just like with just about anything ethnicity out there but of course there are dominant over arching elements which still cluster them together as one ethnicity. Sub-ethnic groups/clans/tribes are a universal phenomenon. Aren't Tajiks still Persians; Aren't Wodaabe still Fulani; Aren't Bedouins still Arabs; Aren't Adyghe still Circassians?
Speaking as someone who's of Texas/Louisiana Creole heritage I can see you're a little foggy on who we are. As US creole-culture isn't specific to Louisiana, let alone just New Orleans, but more of a "Gulf Coast"(and even that leaves out some people) heritage. The "Creoles" are simply what French and Spanish slavers referred to people of African descent who were born in the colonies as apposed to the noncreolized African born people- These distinctions made a difference in the price that individual slaves drove on the market. And even creole culture today is not a monolith nor has it ever been as creole culture is SW rural Louisiana is noticeably, to creole people of course, different then that of New Orleans(even with different wards in the NO there are 100s of year old neighborhood and family specific practices), and creole culture in Nacogdoches, TX is even more distinct than both of them due to the higher degree of non-Isleno spaniard influences vs the French influences in Southern Louisiana. But regardless it's still apart of general US creole culture and by virtue the general African-American cultural continuum.
Edit: Even Southern Atlantic coast Gullah/Geechee culture isn't an %100 monolith as I'm sure that the Charleston, SC geechee culture is noticeably different than that of the Sea Islands, and even more so with Geechees in Florida due to the history of maroonage there.