Just a quick heads up; when adding a reference, it is common practice to use an abbreviation after the equals sign so it is easier to re-use the reference later on. A list of abbreviations can be found here.
Because while his ethnicity may be FN, we still don't know if it is his nationality. For example, look at Tenzin. He has Water Tribe as part of his ethnicity, as well as Air Nomad. However, he has niether of those icons due to the fact that he is not part of those nationalities. Instead, he has the URN icon, because that is his nation. For Iroh, since we still don't know if he resides in the FN, or if he is a URN citizen, it would be speculative to add the FN icon right now.