Looks like Marvel is starting a new trend: announcing in their casting press releases the casting of the actor, but not who the actor is playing. They did this when Rosario Dawson was cast in Daredevil and we had to wait until New York City Comic-Con months later to find out who she was playing (Claire Temple) and they did this to Daniel Bruhl (who they have not officially announced that he's playing Baron Helmut Zemo).
I bet they do this with Chiwetel Ejiofor if he's announced for Doctor Strange, they announce his casting in the film in a press release, with Kevin Feige saying good things about him, but not announcing his character in the film.
It's probably going to be an annoyance.