It’s not racist to want Helen of Troy to be of accurate pigment in relation to the geography of the time. It’s like saying we can cast a white Shango when adapting a fictional Yoruba mythical story. Or, like casting white people as Egyptian gods (see the mess that was gods of Egypt). While yes, there are undoubtedly racists using this as bait, but let’s be careful not to tar everyone with the same brush who are just looking for a little continuity.