No. Make Shuri, Nakia, or M'Baku the new BP. Have a ceremony at the start of the movie to mourn the passing of T'Challa, in honor of the passing of Chad. It can even be written in a way to bring awareness to the seriousness of colon cancer, as no superhero is going to be immune to cancer...except maybe Wolverine. Then pass the torch of BP to another of Wakanda's warriors. I feel like M'Baku would be most-fitting, both because Winston Duke is a familiar face and a good actor, but also because the story of the Jabari tribe taking control of Wakanda opens up so many storylines. M'Baku would still have feelings for T'Challa, who spared his life and made him a better leader. And T'Challa's family would still remember that M'Baku helped to save T'Challa's life. So it allows for a working relationship with Shuri still as the head of the Wakandan tech division, and Nakia still being involved in the country's politics.
I think it's really difficult to try to carry on like nothing happened, and I don't like just changing to another T'Challa. Like it or not, Chadwick Boseman claimed ownership of that role. It is his, and T'Challa died with him. Based on the bank the first movie made, it's safe to assume that the majority of fans of the first movie are not comic book fans. So this decision has to be made from a film-centric perspective, and made to serve the movie-goer, specifically the black movie-goers. Yeah, some people are gonna feel some kinda way about me saying that, but the truth is that T'Challa became more than a movie character in the black community. T'Challa and Wakanda are symbols. So, I think if tastefully done, we can move on from T'Challa, leave that memory and symbol intact, while forging ahead with the story of Wakanda, and it's role in the overall MCU. M'Baka as BP could still embody much of what T'Challa believed in, with probably a bit more of a hawkish edge. Maybe slightly more likely to engage in combat over diplomacy than T'Challa, which would be perfectly fine with the utter chaos that the multiverse should unleash.
That's just my opinion as someone who doesn't read comics, but watches all the Marvel films and shows. With a talented director like Coogler, I think this pivot can be made flawlessly.