Eastern Turkey isn't as rich nor as populous as Western Turkey and so don't need more cities.

And Turkey doesn't need more cities.

But if they were to get A city it should be in the west.

Probably not.

In fact, Diyarbakır and Erzurum were more important and had higher populations than most provinces at that time. Türkiye feels very vulnerable in its current state in the game. The Italian and British navies can very easily destroy Türkiye's economy.