I think the "Caped Crusader" nickname has probably gotten too associated with the 60s Adam West series for them to seriously consider it as a title.
That was 50yrs ago. It's not on DVD and I'd be surprised that its playing in many, if any, markets in reruns now. Seriously, if that is at all a reason its a dumb one. I recall all the fuss about "No one is going to know what/who The Dark Knight
is" when that title was announced. Amazing what proper marketing can do.
Proper marketing would once again let people know this movie(Caped Crusader or Shadow of the Bat) is the followup to Nolan's The Dark Knight