Well, sort of. Concept art has been revealed at Siliconera (see here) that Algol and Edge Master will be returning. As for Devil Jin, not the character himself, but his "style" will reportedly be available in the character creation, as Tekken producer Katsuhiro Harada's likeness has been put in game as a fightable NPC outside of the story mode. Also you have to beat Harada in some offline mode to unlock that style and an achievement from what I've heard.
Personally, I think Edge Master is alright (have to have an all-random character), but Algol was one of the lamest fighting game bosses out there. I can't think of anyone who actually wanted him back, but maybe I'm wrong.