Yeah… because they don’t turn down projects if it looks like they can get them made. Again, when it became “his” script, he very obviously took a colorblind casting to the approach because he was only adapting that one novel. And Vandermeer knew what he was writing and said nothing about it. By the time Portman is cast, it’s not like you want to ruin your reputation pulling out of a greenlit production.
This isn’t even like casting Katniss as a white blonde even though she’s “olive skinned” in the book, or casting a whole bunch of white people as Egyptians in the opening of X-MEN APOCALYPSE (or the entire cast of GODS OF EGYPT) or Jake Gyllenhaal as the Prince of Persia. Instead, it is a movie where diversity is a big part of the film just in the trailers.
Ironically, even though he didn’t read the second novel, he casts Benedict Wong in a role that is actually not Asian in the book.
So, for me, it’s just an example of colorblind casting, not whitewashing - a movie that people interested in diversity should take heart in rather than tearing it down.