Originally Posted by
Blind Wedjat
They can do a lot more with M'Baku now that he's an ally than the pretty generic villain he usually is depicted as. And it's not as if M'Baku and the Jabari pose any real threat to T'Challa who has better armour, weapons, numbers, and powers. The movie has the advantage of really thinking about how things can work and make sense in its own depiction of Wakanda and it doesn't have to adhere to comic book continuity.
M'Baku can still remain a traditionalist, but now the MCU can explore what he brings to the table as a member of the of T'Challa's council. Keep in mind that we never actually saw him complain about Wakanda aiding the rest of the world. He initially has problems with who is in charge of things, that being Shuri being in charge of the Wakanda Design Group and T'Challa being on the throne (because he failed to save T'Chaka), and he also feels T'Challa asking for the Jabari's help was opportunistic seeing that past members of the Royal family have ignored them.
Essentially the Jabari are the minority group with no political power or influence possibly because they worshipped a different god and refused rule from T'Challa's ancestors. Now they do have some power because their leader M'Baku has made it to the King's council. And considering M'Baku has led the Jabari to fight for the world on T'Challa's behalf three times, I fail to see why M'Baku would have a problem with Wakanda aiding the rest of the world. Yes, no one knows what he may have been thinking for those five years when T'Challa and Shuri were snapped, but keep in mind it's about two years between Black Panther and Infinity War and M'Baku still didn't hesitate to defend outsiders T'Challa brought in to Wakanda. In fact, who is to say the Jabari didn't want Wakanda to help Africa during the Transatlantic slave trade and centuries after that? The only people we see spouting nationalist and isolationist rhetoric are the Royal family and their allies (exceptions being Nakia and possibly Shuri), not the Jabari.