This is highly, highly speculative, because of the long passage of time, almost a millennium.
But please, speculate away...
What if Turks never made it past the Taurus mountains for any sustained period and Anatolia remained Byzantine?
When we get to the age of nationalism by the 19th and 20th century, is Anatolia linguistically entirely Greek, with the population largely identifying as Greek by nationality, as Greek as anybody from athens?
or are there any residual pre greek languages or ethnic identities remaining (phrygian, lydian, cappadocian, galatian, pontic, Kurdish, Armenian etc) ?