I'm all for using the very underused parts of Earth's cultural history, but there's an angle that's both "it won't sell because are not familiar", that is also way too similar to the "no minorities, they should just make their own games and not dilute the racial purity of our games" argument from chuds.This whole Stellar Blade thing reminded me why I really don't like talk about diversity, inclusion and similar things these days. Major part in it is that everything is done by US standards and everything is rated by US standards. This is kinda most noticeable regarding black characters where entire US history of slavery is pushed worldwide issue for example.
Also my personal opinion is that most things in games done these days regarding diversity and inclusion is performative, done for earning points. For me if you really want to make things diverse that is not just dropping characters in games and entertainment media by modern standards in products regardless of theme, setting and period. Why don't we see games and other entertainment products set in some historic period of Africa? Example 13th century East Africa where we could explore history of Ethiopia where Ortodox Christians clashed with Otomans. Or rich history of India and Middle East. That is true diversity and inclusion in my opinion, showing entire different cultures and history.
Our world history is so rich and full amazing stories and events to draw inspiration from them, yet entertainment industry is sticking to same things over and over again.
And things are changing, we got just that this year in PoP: The lost crown and Tales of Kenzera: ZAU... and they were published by Ubisoft and EA, not exactly indies.