You'll find Naan recipes using only yeast, recipes using sourdough starter (which is also a yeast, btw), recipes using only baking soda, recipes using baking powder, and recipes using a combination of all leavening agents - if you search hard enough.
It's thinkable that a BIR would not use a yeasted dough because it could over-rise easily. Then again, Pizza shops always use yeast and they can use their dough all day. Most BIR recipes for Naan (I think I have more than 20 of them) use either Baking soda or Baking powder a combination of both. Some also use a tiny bit of yeast.
I don't think you'll find a BIR that uses a sourdough starter, though... have you ever used one? They are a lot of work.
I'll stay out of this discussion from now on so as not to turn off any others who might have "better" input.