From a distance all of the Franco people "look" the same. Zoom in and you will see differences within a region, Parish, and even towns. The Acadian Creoles in Houma, Golden Meadow, and Abbeville are a little different from the Acadian Creoles in Iota, Breaux Bridge, and Church Point. The French Creoles in Evangeline and Avoyelles are slighty different from each other and from the Acadian Creoles. Different dialects of Louisiana Creole, customs, etc. Slowly zoom out and we all begin to look the same.
So, Louisiana wanted to promote the Franco area for tourism and had to unify, promote, and label the area. Acadiana was chosen as a regional name. Cajun was chosen as the label. They had debates on what to label the area and what to call it.
2006. The Fontenots, Lafleurs, Guillorys, Deshotel/Deshotels, Vidrines, Soileaus, Berzas, Bordelons, Rabalais, Lemoines, Brignacs, etc, etc, etc, still did not come from Acadie. They intermarried with other French Creoles in the areas of Evangeline and Avoyelles - where they were the majority cultural population.
Things might be changing now. But that is the history of the Franco areas of Evangeline and Avoyelles.