It doesn't sound good for the project that such high profile actors are turning it down. It's even more embarrassing when the studio starts to look for big names that they'll never get. It's going to be an expensive production and a massive gamble for the studio. It's been hammered for over a year by fans of the original material because the studio had been changing major elements of the story. First of all setting the story in Manhattan and not Toyko allowing to recast the expected Asian cast with white folks.
I've never really had issues with ethnicity when casting fictional characters. Yet this one is hard to swallow because it's identity is Japanese. There are links to the bombings of Hiroshima and Nagasaki which is beyond important to the country's psyche. It's not like with Nick Fury, Hemidall (Thor) and Goku (Drangon Ball) where the background of the actors didn't really matter because it wasn't important to the story or setting. I have to admit I've been an avid fan of the anime for years and I believe focusing on the manga source material should be priority number one. It's also possible it's a way for the studio to save money as shooting in Japan is a very expensive process. There is now word from Variety, Steve Cloves (Harry Potter Films) has been hired to "polish" the script. I really hope they listen to the fan-base that would support this film and bring back the original elements.