Many things that are legal are of questionable ethics. Asking permission could easily just be an effort for them to get better samples of her voice. Pulling the voice after debuting it is 100% a PR response. If there's a law that was broken, pulling the voice doesn't unbreak it.
Public figures own their likeness and control its use. Not to mention that in this case OA is playing chicken with studios as well. Not a great time to do so, given their stated hopes of supplanting 99% of existing Hollywood creatives.