He made the initial diagnostic test sound like it has a massive impact on what you'll study. It doesn't. Even if MA thinks you know a topic well based on the diagnostic test, that doesn't mean you won't encounter it again. He seems to have missed the fact that every time you answer a question, this affects the estimate that MA has about your comfort with one or more topics.

The excessive focus on procedural fluency is a reasonable criticism but, as I said in another comment, this doesn't bother me at all. There are plenty of other sources for this. And procedural fluency is a good enabler for developing conceptual understanding.