Black Panther was the Marvel movie we had all been ... Killmonger believes that he has a claim to the Wakandan throne, and so, he challenges T’Challa to that. He wants to continue his father ...

The implication appears to be that going forward, M'Baku will rule as king of Wakanda, while Shuri will still be Black Panther, and he's presumably seeking the throne with her permission.

Marvel Studios has released the official trailer for "Black Panther". The film features Chadwick ... must succeed to the throne of the technologically advanced African country of Wakanda.