Why are only 8 episodes dubbed???
why are only the first 8 episodes dubbed if the entire first season is complete?
Because the series is currently on Toonami, Funimation is uploading new dub episodes after they air on TV.
Attack on Titan is an exception to Funimation's advertised "Watch Dubs before DVD & Blu-Ray" feature of their subscription service as 1-13 are already out on the bluray that has been out for the better part of a month :(
It was a special occasion, since the dub showed on Toonami before it was released. FUNimation's gonna keep the pattern of releasing episodes as they air on Toonami. Don't worry, it'll pay off when Part 2 airs and Episode 14 is on EVS before Bluray.