Even when DCEU tries to do their own black super hero lead, it will not nearly hit as big as Black Panther. Black Panther was so rooted in Africa and the message resonated so well with the black folks. Besides the tech, the film was grounded in reality. Green Lantern is so sci fi and all about space stuff. It wont have any African culture or african roots like Black Panther.
I don't think this is brought up enough, what made black panther interesting too me was the very different visuals, culture setting, and the fact that it became a little bit more meatier than the average marvel film.
On top of having a black lead hitting the other side of the coin, it's well put together film.
I don't think a black american super hero would have done nearly as well, as I do think a big selling point of this film was the different visuals, culture expressed, and the fact that it had too loosely touch upon political issues.
And for the people who liked entertaining movies, hey its the first african super hero. Thats pretty cool to say too.
DC's closest character will be Aquaman too BP, in that it can deal with race relations, have a non-white lead, and have too touch upon some sort of politics and deeper meaning given that he's a king (much like BP) but other super heroes get around.
Black panther is a very unique character in that sense compared too most of DC's rosters, do I think there will be a black lead DC movie? Sure, I don't see why not, whether its GL, Cyborg, or they make a some what known character like spectre, hawkgirl, or Connor Hawke, film, almost none of these are routed in African culture.
Is there a push in general for diversity in comics? Yes, so I don't think it's DC copying Marvel.