Can you explain what you mean by this? I have never heard the term "documentation theater", yet it seems like you're using it pejoratively here. The Microsoft version has a summary of the intended purpose of the class, a brief code snippet showing what its use might look like, images demonstrating the output of using the class, and lists of all available constructors, properties, and methods along with a brief description of each. If this is "documentation theater", please sign me up for more.

His point is that none of those things actually tell you about the class, it’s just theater. If you want to know what it really does, you need to look at the source code, that’s where the truth lies.

I disagree. The images showed me what it does, or at least gave me an idea what it would do.