M’Baku returned in Avengers: Infinity War to fight alongside Wakanda’s warriors and the Avengers against Thanos’ hordes, and he was among the half of the universe that survived The Snap.
Later in the movie, M’Baku became an unexpected ally to T’Challa after he was overthrown by Killmonger.
Granted, he was initially unwilling to help T’Challa take back his throne, but M’Baku and the rest of the Jabari eventually provided some much-needed assistance at the last minute against Killmonger’s forces.