There are a lot of questions about what the future of the Black Panther franchise will look like following the death of Chadwick Boseman. However, while the plans for Black Panther 2 are, without question, going to be going through some significant changes, the film does not appear to have been significantly stalled. Pre-production continues to move forward and it's now being reported that the first new star has been added to the franchise. Tenoch Huerta of Netflix's Narcos: Mexico is reportedly in talks to join the cast of the forthcoming sequel.
Tenoch Huerta is the first new name to be attached to the upcoming movie and while a role is not mentioned, THR is claiming that if he signs on, he'll be playing of the movie's antagonists. Since none of the villains from the first film survived, the new movie will certainly need new adversaries to overcome, so this makes some sense. Some sources have indicated that Huerta could be in line to play the Marvel character White Tiger, who is not traditionally portrayed as a villain, though certainly it wouldn't be the first time the MCU took an established character in a new direction if that's the case.
While new villains will certainly give us an idea of what the next Black Panther movie has planned, the bigger questions are certainly going to be surrounding what the plan is for the title character. Early indications are that Letitia Wright's Shuri will be taking on a more prominent role in the new movie, perhaps taking on the Black Panther role herself. That certainly makes some sense, it's happened in the comics as well. Marvel has yet to confirm anything beyond the fact that Black Panther 2 is still happening, The one exception being that the movie will not use a CGI version of Chadwick Boseman's character, even briefly to explain what happened to him.
While the loss of any actor for any reason in the middle of a popular franchise is going to be a difficult thing to overcome, the death of Chadwick Boseman is particularly complex. Black Panther wasn't simply a movie but a cultural moment. The sequel was going to have to do something truly special simply by existing considering what it had to follow. Now, that's all going to be that much more difficult.
And of course, since the Marvel Cinematic Universe is a massive entity, the loss of Chadwick Boseman doesn't necessarily only impact the Black Panther films, but it can also mean changes for whatever storylines were being setup for the larger universe. It's possible that simply inputting the new Black Panther would work, but it's also possible that a lot more will need to be changed going forward.