With the Iran example, it's an interesting world we live in where the design of an emoji by some of the largest companies in the world can support or detract recognition of new states. Especially with some of these tech companies bending the knee to the current US administration I could imagine a world where there are executive orders to say, remove the Greenland flag, or change the design of the Venezuela flag.
Well the Taiwan flag doesn't appear on mainland china phones, I think the phone does fall back to the TW letters.