User blog comment:IamJakuhoRaikoben/Sorcerer Magazine, Issue 29: May 2014/@comment-4449950-20140602011710/@comment-2214433-20140602115227

No, SnK spin offs aren't included. And also, Oda has taken a lot of breaks, so that's the reason, I suppose, as well as the dates of releases, I know that SnK #12 went out in December and #13 in April (Do note that for the manga industry, new year starts in December).