The main hub of the Chromie scenario takes place in the future, in her own words. The Legion is still a threat there, trying to kill her with the Nightmare, Void Lords, and Scourge. That's pretty much the only lead we have, and we don't know how far into the future the scenario takes place.
Demons will probably pop up as enemies and occasional tenuous allies (like Valzuun, or the DH/Warlock order hall champions). The Legion may still be a thing, as well, but without the leadership or organization it has now. Demons will still be around to be annoying, they still have the idea to wipe out life in the universe instead of the Void Lords corrupting everything.