What do you mean "official latin name"? Seems to me the only Latin alphabet language without diacritics is English, but then we do use them in English for certain borrowed words (façade, piñata) or fringe uses (coöperate). I wonder how these are handled in a context like the UN where multiple languages are used.
Most countries that use more than the standard latin script have at least one version of their name in latin so that everyone else can use it. საქართველო, Ελλάδα, Россия etc aren't very usable written like that. I would understand if Turkey applied for the romanized version of their name but using diacritics in it makes it a pain in the ass for everyone else.
> I would understand if Turkey applied for the romanized version of their name
This I just don't understand. Turkish is written in a Latin script with a few diacritics (and the extra character of the i without the dot.) It's hard to call any modification of their existing script a "romanization".
As for some of your examples, eg. Россия, I don't think they use a romanization of that word like Rossija or Rossiya at the UN, I think they use English or French translations of Russian Federation.
And in english it's "Ivory Coast", in german it's "Elfenbeinküste".
None of those is an official name tho, they are quite insistent that's exclusively the french one:
>Therefore, in April 1986, the government declared that Côte d'Ivoire (or, more fully, République de Côte d'Ivoire) would be its formal name for the purposes of diplomatic protocol, and has since officially refused to recognize any translations from French to other languages in its international dealings.
Funny to note is that this sometimes goes wrong, i.e., in Dutch we have a Witte Neushoorn (White Rhino, or, White Nosehorn if you will), however, this Rhino is not white but it has a wide mouth and English people call (or called) it Wide Rhino... Somewhere someone misunderstood and now we have a White Rhino that is grey.
What do you mean "official latin name"? Seems to me the only Latin alphabet language without diacritics is English, but then we do use them in English for certain borrowed words (façade, piñata) or fringe uses (coöperate). I wonder how these are handled in a context like the UN where multiple languages are used.