User blog comment:B214/Question and Answers 6/@comment-3285616-20161121005601/@comment-9595671-20161122224810

Well, be it those or Season 4, we'll atleast get to see a few more characters getting animated. Though I get the feeling Slash/Dog is the least likely as while canon to DxD, it's also it's own thing. So it would probably be announced getting an anime by it's actual name.