So now we know that they tried to license from Scarlett Johansson directly but didn't reach agreeable terms. Sam has a lot of plates spinning, other plates are much more important but of course they should have done better from the start, and I'm sure they know it. It's not the best possible voice. Personally I really like a few from the 110 in the VCTK corpus from University of Edinburgh. They're used in a few places, I assume there are no license issues, and they could hire and re-record the best anyway with more emotion samples. It's funny they have a set list of voices rather than a space of voices that people can choose from.