This is true, though I sort of despise the decision. The Civ design and heritage is solely based on the ancient Greek kingdom of Macedon, while the music is solely based on North Macedonian folk music. This results in a mish-mash that does nothing but open the door to nationalist revisionisms.
He was in a difficult situation, though, seeing as there was already an Ancient Greek Civ competing with Macedon for a limited amount of written music. I can understand not wanting to repeat yourself in that way. And truth be told, I really enjoy what he did. The arrangements are fantastic and introduced me to some interesting music.
I still disapprove of the rationale behind it, especially when on a music theory level there were actually Greek choices that match the Slavic choices in time signature, tempo, and mood. It’s a little frustrating.