We are using Tableau visualizations on our site. Accessibility has been a huge problem and I have many as yet unresolved concerns. There were some improvements to the latest version 10.3, but many of the improved
features were only available if you were using the Tableau Server, not the free public edition. If you can’t make the entire dataset available for anyone to download, then there is nothing available to screen readers for complex data sets, which are, of course,
what Tableau is designed for. I was unable to resolve our accessibility issues using the public edition. If you are using one of the paid versions, you will probably have more luck.