Just downloaded Greece and searched for Athens. In OSM it has name=Αθήνα, name:en=Athens (and others). When typing Athen it displays “Athens(Αθήνα)”. It seems that all places in in Greece have a name:en. But yes, will be interesting to see, how it deals with name=cyrllic and name:sr-Latn. The maps are usually updated each months so I expect them soon