Fullemetal Alchemist is getting a live-action movie with an all Japanese cast. Interesting to see the contrast with the american Ghost in the Shell - is this reverse white-washing?
Fullmetal Alchemist is a constructed setting, but they do have a clear analogue in late 19th, early 20th century Europe. This is kind of a complicated question - does it matter what ethnicity the characters are? Avatar got a lot of shit for whitewashing, but the characters existed within a constructed work where there aren't any obvious ethnic/racial analogues (maybe the Water Tribe and the Air Nomads had real-world analogues, but it's not clear to me that the Fire Nation or Earth Kingdom have clear parallels).
When the GitS movie was announced, I was actually thinking that the right approach might be to totally Americanize the movie, to create an alternate version of the setting. While GitS has a lot to say about Japanese culture, I think the focus was much more on future society and the interactions between humanity and technology. In some sense, the Major's nationality is just a small part of her character - we could still have an interesting and faithful adaptation of this character who was born in New York. Just like how the character Washizu Asaji is a faithful adaptation of Lady Macbeth, but born in Sengoku Era Japan.
I'm not going to defend whitewashing too much, since I think Hollywood mishandles it constantly. It is especially egregious in historical movies. And it is particularly weirdly implemented in the live-action GitS, where the seemingly American character Mira Killian discovers that she was in fact re-built using the brain of... Motoko Kusanagi. And that would actually be a very interesting premise, if only they did something with it, instead of just using it to justify why they're using an american actor. It would be like if RoboCop discovered that he was rebuilt from the dead body of a black police officer, but given a white face... and that never being used in a satirical way within the context of the movie universe, but instead just done because movie studio thought a white RoboCop would make more money at the box office.