Just a guess here. But I think they’re ramping up the rhetoric because Russia wants to hit Turkey from two sides — north and south.
In the south they want to have a secure port and ally in Syria and from a new Kurdistan carved out of Syria and Iraq and a big swath of Turkey. The Kurds have the ability to fight and winning protect their own state. They would want access to the Mediterranean, too, through a corridor passing the parts of Syria and Turkey.
On the north I think Russia wants to seize all of European Turkey and also deep into Asian Turkey taking Constantinople. They would secure their access from the Black Sea to the Mediterranean for all time. Europe is too weak to object and the Muslim invasion may lead some of them, like France, to prevent NATO from getting involved.
In time Russia may want to swallow all of Turkey after taking a chunk of the north and south and crush the Islamists and send in a million Orthodox missionaries to reconvert the nation to Christianity. (In my dreams, I realize.)