Comics

That is canonically what happens, with the earth and fire benders coming together and reorienting the class structure such that benders are superior to nonbenders. This is further explored in LoK before being handwaved away at the end of the first season (which is generally how each season goes, there is an interesting premise which is explored before being completely abandoned with some plot convenience that doesn’t actually address the underlying issue or premise and doesn’t make sense as a resolution if you think about it)