I know that Braveheart and Gladiator are not historically accurate. The distinction that I'm pointing out is that there is a difference between historical inaccuracy for the sake of entertainment/narrative, and white-washing. In Gladiator and Braveheart the historical inaccuracies are things like "those uniforms didn't exist during that time period", "this character never existed", "actually this king was killed by this guy and not that guy" etc. Arguably the greatest inaccuracy about Wallace is that in the film he's portrayed as le humble farmer man whereas in reality he was a nobleman.
That's a far cry from sweeping the principle reasons for the conflict under the rug for the sake of a good vs evil narrative. The Dahomey were a facist empire whose ENTIRE economy was built upon invading their neighbors so that they could sell them into slavery. The King's Wives regiment that the movie is focused on only existed because the Dahomey had sustained so many losses from invading their neighbors that they were desperate for manpower, and one of their chief duties was to break slave-revolts and capture more people to enslave. The wise and troubled king that we see in the trailers for the movie personally decapitated hundreds of enslaved children per year, every year, as part of a Voodoo ritual that had been a core part of their society for over a century.
Say what you want about Gladiator but Roman society was portrayed in the movie as a bloodthirsty people who enslaved others and forced them to fight to the death for entertainment. The Roman nobility were depicted as conniving backstabbers. Yes we don't know what this film will portray, or not portray, but that doesn't change the fact that the story of the Dahomey-French war is a tale about one of the greatest evils the World has ever known getting their just-deserts. Would you really just shrug and say "well you know no movie is historically accurate" if Hollywood put out a movie today about Nazi soldiers heroically slaughtering hundreds of Russian troops as a desperate last stand in the Battle of Berlin? "Christian Bale stars as Adolf Hitler and Chris Pine as Lieutenant Fritz in this epic tale of the brave German peoples' defiant resistance against barbaric Communist aggression... coming soon to a theater near you".
And yes I'm aware that this entire conversation is just speculation since we don't know anything about the movie yet. But these are my initial thoughts upon seeing the trailer, and I would be very surprised if the heroes are portrayed as the cartoonishly evil individuals that they were in real life. It's crazy that this movie could even be considered black empowerment when this Empire was one of the greatest contributors to the Atlantic Slave Trade. One of the kings of these dudes literally helped the Portugese assassinate his Dad (or maybe brother) so that he could take power and become King, because he and the Portugese were worried that the old King was going to outlaw slavery.