I don't know how many of y'all actually followed other shows/movies through the years but actors die and get recast all of the time. If people can't suspend disbelief over a fictional character, then you've already failed to capture their imagination.
Hell, as huge as Harry Potter was, Richard Harris died, and Dumbledore was recast to complete the production schedule. He'd already been in 2 films at that time, AND he was a legend. You don't think that didn't hit the cast, especially the children, hard?
But no matter what happened, there would still be comparisons. This movie will be compared to the first. Namor will be compared to Killmonger, had there been a new actor as T'Challa, he'd be compared to Chadwick. Hell, if Chadwick not died, he'd be compared to his portrayal in the first. His portrayals between Civil Wars and BP1 were already compared.
But, after watching the film, how many agree that this felt like a Swan Song for Wakanda overall?