Sasuke asked Itachi to show him how to do edo tensei release it was stated in manga. Sasuke watched the hand signs carefully he knows the release. just like he knows izanami and izanagi. I'm pretty sure he can preform edo tensei because he watched it be done infront of him with his sharingan activated, but we will never know until kishi shows us but I'm going to say he knows Edo Tensei and its Release. Because he specifically asked itachi how to release because he knew he was going to need it later hence look at where he is now...makes sense right?