I think the best scenario for Turkey would be Facebook and Google deciding to pull out their representatives from Turkey.
Legally the next step of Turkey would be to block %90 percent of the traffic. Which would be equal to blocking these sites.
There is a lot of AKP/Erdoğan supporters that use these services. This would weaken Erdoğan further.
Most educated people in Turkey do/can use a VPN anyways. Only Erdoğan supporters, which are known to have less/none education (big surprise) would be effected from this.