Fantastic Beasts 2: 10 Biggest Changes To Harry Potter Canon (And If They Work)
4. Dumbledore Taught Defence Against The Dark Arts
The Change:
While it's always been believed that Albus Dumbledore was Transfiguration teacher prior to becoming Headmaster of Hogwarts, The Crimes of Grindelwald shows he initially had a different role: Defence Against the Dark Arts teacher. We know he has to become Transfiguration professor eventually, because that's what he teaches when Tom Riddle is at the school, but apparently he taught DADA first.
Does It Work?
Not really. It isn't the biggest or most egregious change, especially taken in isolation, but it does mean that the film needs to find a slightly convoluted way of getting him out of the position (and means the Ministry is interfering at Hogwarts long before Dolores Umbridge turns up). It's included to highlight what the Boggart turns into for Leta and develop her story further (and a little of Newt's, too), and show that the Ministry doesn't trust him, but it doesn't feel necessary and becomes much worse when wrapped up with another change.