A small excerpt from Allanaki Fashions and another reason I really like the idea of this change.
To this end, loosely woven and light fabrics worn in layers are utilized as daily wear to ward off the worst of the sun and sands. Many types of overgarments are worn in long layers, protecting the flesh from the harsh rays of sunlight and the pervasive heat.
Commoners often look to nobility for examples in most aspects of life, and fashion is no exception. The styles of commoner clothing available, while simpler and cheaper, often imitate that of nobles. For example, while nobles often wear ornately decorated silks and other lush fabrics, commoners wear cottons, sandcloth or other inexpensive textiles. Another difference in commoner attire is that it tends to be looser, more comfortable, and less hindering, in order to be practical for everyday use.
Some clothes unique to Allanak include wrapped pants, long tunics, kalasiris, long kilts, and many types of over-garbs, often worn in layers, are also commonly seen in the South.