The 9 questions that uncover the most surprising insights from employees

As to this:

“Have you seen someone here do great work that’s gone unnoticed?”

This is best handled by anonymous upvoting. Give every employee the power to upvote 3 people each month. That way the management can see if there are some "unknown" people who are getting upvotes.

Also, every employee should be given the power to anonymously downvote one person each month. This is the best way to find cases of racism, sexual harassment, and plain incompetence. Often with issues such as sexual harassment, people won't come forward because they don't have enough evidence, and even if they did come forward, management would be faced with a "he said/she said" situation (or "he said/he said" or "she said/she said"). But a persistent pattern of downvotes, over the course of months, tells management that an employee is problematic in some way, even if that employee does good work and, when management is around, demonstrates good behavior.

Feels like blatant self promotion. Yet another type of slashvertisement.

They're yes/no questions that don't provide any clues as to what/where/when/who/how…

The problem with this is that it does not address the fact that while employee feedback may provide some insights that are more or less useful, it does not do anything to help a manager decide what to do about it. That's where real managerial skill provides value, but these questions don't get you any nearer to the answer(s).