They legally become migrants? According to what law? Here's the definition of a refugee according to the amended 1951 Convention on refugees UN High Commissioner for Refugees
And here's an expanded definition recognized by the UNHCR
And here's what they say about the cessation of refugee status
And later on adds
http://www.unhcr.org/46f7c0ee2.pdf
The Syrian Civil War is still ongoing and there's no reason to think every single one of the 2 million refugees in Turkey has found a durable solution since many have not been resettled and do not have a status that corresponds to that of a Turkish national.