Avatar Studios hasn't said a word. Nor has Paramount. This was supposed to be the grand launch of their big new animation push for the franchise and they clearly spent a lot of $$ on it...so why not even so much as a squeak?
and Dante Basco is fucking Filipino which is close enough to the generic non-specific "Asian" culture of the Fire Nation but I'm guessing he wasn't down with recasting everyone else (or maybe they didnt approach him at all)