People of today's Macedonia by blood are same people as those who lived there thousands of years ago.
They did not disappear. Therefore, I believe they have claim to heritage of ancestors who lived there before.
Genetically, Greeks, Serbs, Macedonians and Bulgarians are all similar, since they are descended from Paleo-Balkan tribes (Greeks, Illyrians, Macedonians and Thracians), who were all related and native to reigon.
Fact that they speak Slavic language is because of Slavic conquering in 6th century (invited by Byzantium to fight Avars, according to Slavic migration theory), but that does not mean they magically changed into Slavs like those in Poland, Belarus, Ukraine or Slovakia, their blood and ancient heritage still remained with them.
wilkolak, people from the country that you are talking about can be the same people as those who lived there since palaiolithic times, this doesn't change the fact that in this area,the people were everything else except of ancient macedonians, and macedonians were Never, never settled in these lands.
Most of them were Paionians, a thracian speaking tribe which was considered fully barbarian by Macedonians.
there were also many dardanian cities like Skopje (it was known as Scupi)
So how is it possible people that live in a country that has never been home of even one macedonian in the whole history? (since as we all known the ancient people there were paionians and later slavs, but not even one ancient source proves that there was even one macedonian settlement there)