No. One last attempt.
"Should a low-level character remember to breathe?" is a question that would appear for only a few campaign styles. It would not be asked in the grand majority of cases because in most campaigns it would be nonsensical.
In much the same way, "Should a low-level character know to burn a troll?" becomes nonsensical if the table has already determined the answer is "everyone does" or the answer is "no one does". Those tables do not require any model other than the answer "yes" or "no" in much the same way almost every table would not require anything but the answer of "no" to the first question. The model is trivial: there re no inputs that affect the output.
There is nothing wrong with your answer for campaigning. I merely pointed out assigning the assumption's insertion to lowkey13 was incorrect. For the question to have a non-trivial answer requires the questioner to be faced with uncertainty.
Lowkey13 presented 3 non-trivial models (as in there are inputs that affect outputs) previously commonly used for those tables where the answer was not globally predetermined. It matters not what the default answer is.
Again, there is nothing wrong with using a trivial model and predetermining global answers. There's nothing wrong with swapping the default answer and using a non-trivial model (though swapping the default answer typically accomplishes little from a modelling or logical perspective).
Man, this is a pretzel. Okay, let's break it down.
The OP question is pretty straightforward. It asks a question, which you've quoted, that has no uncertainty component. It gives two possible answers, yes and no, neither of which have any uncertainty component. Yet, you're insisting that answers to this question are trivial absent an uncertainty component. And that "yes" answers fail this and also "no" answers fail this. So, since, due to your assumptions about what a valid question is, you've decided that only uncertain answers are valid, despite this not being in the OP. And, you've decided that you'll be the person to police answers you think fail this and tell them they're not good answers to the OP. Despite not being the OP, and the OP having explicitly declined to add any such requirements even when asked. So, let's be perfectly clear, this is you, not the OP question. Now that we have removed the shield of the OP, let's address your other points.
You state that a general question to a message board must have answers that have uncertainty, because non-uncertain answers are trivial. You say these answers are trivial because, in a game where they were true, no one in that game would bother to ask the question. I agree, however you've committed a pretty big category error here in that the question from the OP isn't asking me to to answer myself in my own game, but is instead polling all possible games. To which, a 'yes, always' answer is not trivial because it informs that such a game exists. So, that axis is flawed.
Finally, let's deal with the specific. You say
@lowkey13's answers are good because they contain uncertainty. Mine is bad because it doesn't. However, this is a strawman of my argument you've presented. I clearly lay out in my post that the presumption should be that the PCs know, and that it's the DM's job to present that information in game. I do, however, note that if this is done and the PCs fail to engage it, then the lack of important knowledge in on them now, not the DM. I say this because I feel secret knowledge about encounters that PCs cannot discern is playing gotcha. I made these points in my post which started your argument that I had failed to answer the question. So, this line is flawed because it argues against a strawman of my post to establish a difference you're using to dismiss my post.
So, your entire argument is flawed. The OP makes no need for uncertainty in response. A "yes, always" response is not a trivial response to the question asked in the OP. And, you've strawmanned my argument to categorize it into your already flawed bin of "yes, always" in the face of a more nuanced point.
