>Seems to be breaking with comic book (and film) tradition.

Black Panther is a title. T’Challa is just the main iteration we follow in the comics.

And in the comics, when T’Challa is sick, Shuri takes the mantle.

We see three separate Black Panthers across two movies in the MCU
We see the mantle passed down when one dies.
We also see the mantle change hands via ritual ceremony.

Not recasting, and handing the mantle over to another character, is 100% in line with both the comics and the movie.

So not only is that not a valid complaint, it’s 180 degrees away from every ounce of established canon and tradition in both the comics and movies- particularly with this character.

Spider-Man was never recast with the same continuity. Each recast came with a reboot.
Not only that, that was an exponentially smaller world than what we have in the MCU.

It’s not like there was a credible option to takeover as Spider-Man in the first two franchises.

BP not only has established canon that makes passing down the mantle the logical, realistic, and narratively consistent choice, it also has credible, established options to do it.

Shuri
Killmonger
M’Baku