What is the significance of the stage direction indicating that Amir speaks with a flawless accent in the play, Disgraced?

Amir is a successful American lawyer who has left behind whatever ethnicity or religion his family may have brought here, but this has a double legacy: on one side, it means he has become deracinated—an American who can pass as American by voice. On the other hand, it means he has suffered a cultural loss, as he no longer has the ethnicity or language to go with the skin and appearance that mark him as a non-white person.