Board Thread:Questions and Answers/@comment-27802108-20160219071545/@comment-190.48.126.8-20160411155004

SS ~ does not mean that he's on the verge of being SSS or anything similar. It means that the CCG doesn't know much about that ghoul, so they give him a temporary rank. It means that he is estimated to be around SS level, he could be higher or lower.

On the rest of what you said, Kaneki has been agressive towards the CCG. He nearly killed Shinohara, defeated several squads at the Anteiku Raid, killed Amon (as far as the CCG knows), and now he's released several ghouls from Cochlea, on top of having to defeat Arima if he is to escape alive. Besides this, he has tons of info on the CCG, so he'll certainly be given an SSS rating once this arc is over, assuming the CCG is still standing.