They should just have Okoye take the mantle. She was already running Wakanda and T'Challa's stand-in in The Avengers when he was snapped away during End Game. nikkas need to stop acting retarded about the MCU Black Panther required to be a man. Okoye getting the mantle pretty much changes nothing in the MCU.
Okoye could take the mantle, I'd be fine with that because it would make sense, MCU's version of Shuri, not so much. She damn near makes doing an Ironheart series redundant because she has more in common with RiRi Williams than she does her own comic counterpart. Killing off T'challa after just returning from the snap after 5 years only to have someone who has not shown themselves to be a warrior leapfrog Okoye or even Nakia for the mantle is dumb, but they aren't fan favorites.
And how does he die? Who catches that body and makes themselves forever irredeemable? Namor? Doom?
Wack......