I disagree: Thor was very nordic with a monarchy.
Combining sci-fi with traditional ideals and systems is pretty commonplace.
The Honor Harrington series by David Weber is basically Victorian military but with space ships and libertarianism monarchy. Generally speaking white “futurism” gets more categories and often has throwbacks such as 80s punk fashions in cyberpunk, etc.
An important part of Afrofuturism that distinguishes it from white futurism is it puts different cultural values first and foremost, and explores the pros and cons of those. Otherwise it’s just literally a difference in casting and very limiting.
But why is their super hero movie expected to not have any depictions of anything from African culture or examine anything? How is it “stereotypes” when they got consultants etc to actually provide authentic incorporations of African culture into the ideas? How would it have been better if they’d been more like white people but in Africa?