Realistically, the choice is going to be between Turkey and Turkiye. Most people aren't going to go through the hassle of adding the umlaut. Countries can request that people refer to them anything within reason, and in this case reason dictates that it be constrained by ASCII characters like every other country in the world. I think people might make the exception within certain formal contexts, but not in a random Hacker News post.
You're demonstrating the exact point by showing that they have an ASCII name and an official one. If you're having a regular conversation with someone you're probably going to use Ivory Coast and not the French name.
