IANAL, so I am just guessing.
But I wonder if an argument can be made that by flagrantly violating the license, Microsoft is devaluing the whole concept of the relevant license and similar ones. The entire body of source code that was created partly because of trusting that those licenses mean something is worth an enormous amount.
So I'm guessing the perhaps there could be a class action lawsuit on behalf of the entire open source community that uses that class of license.