Yep. I think it goes further than whether there's a published paper about. It boils down to "does the question have exactly one correct answer?"

One important thing you learn in interviewer workshops is to avoid asking questions with "aha" components, i.e. things that can only be solved if a very specific insight is known. This type of question is problematic because it falls victim to the fallacious assumption that a candidate that excels in one specific problem must necessarily excel at others that are in actuality, at best, only marginally related.

Instead, it is better to ask questions for which the solution can be arrived at with small increments in effort (e.g. maybe there's an obvious brute force solution and you start from there to discuss more optimal solutions, or maybe the candidate got stuck on some specific peculiarity and you can give a hint to unblock them and move on to another part of the problem to get more signal)