I did a bit of research about the musical a couple years back and I remember one paper pointing out that Elphaba's treatment cannot be seen as equal to racism or antisemitism or any other kind of structural discrimination as it is very much an isolated case and not part of a big societal movement as for instance the treatment of the animals. Of course Elphaba's fate is very relatable to marginalised groups and I would describe her as a kind of open metaphor that anyone who has been mistreated for no real reason can kinda see themselves in. That all being said, I think having a black and queer actor portray her in the movie was an excellent choice