One of the things I love about urban fantasy, is that it encourages a reader to travel to fantastical imaginary worlds. Even if the world largely resembles our current society, the addition of vampires, fae, werewolves etc., adds new elements to any story. A writer must interweave their version of our world into their story, to ensure that there is enough context, to allow the reader to relate with the characters. Sometimes, this can be achieved with things like having characters go to a specific location, or participate in a very popular cultural activity like checking email. Some writers however take these connections too far by engaging in revisionist history, and appropriating the experiences of marginalised people.
This can include inserting their protagonist into real historical situations, in an attempt to convey the age of the supernatural in question. Unfortunately, this usually leads to some sort of revisionism as an imaginary character, would have had no role to play for the allies in WWII. Yes, I am looking at you Sanctuary. Kevin Hearne, had his protagonist Atticus play a role in the French resistance. In Eternal Law, Zak became the Angel of Mons (which is based on a real legend), who guided soldiers to safety in WWI, and was then punished for his action by being forced to defend soldiers accused of going AWOL. Rebbecca Hamilton inserted one of her characters into the Salem witch trials, and in Morgan Rice’s Vampire Journals series, she took it a step further and even used one of the historical people from the trials.
The worst of this marginalisation is, of course, appropriating marginalised identities and equality movements. If there were an award for squeezing in the most appropriation in a series, it would have to go to Dan Waters who wrote The Generation Dead Series. Waters has managed to appropriate slurs, appropriate the language of disability, refer to the closet, passing and coming out to describe his zombies revealing their true nature, as well as appropriating the language of the civil rights movement, and appropriating Jim Crow, to apply to the separation of the differently biotic (yes, he actually used that term) and living people.