We have guidance about instructing that we do not allow and will revert any edit that attempts to guess the system of the question and edit it into the question here. We also have related guidance for how to handle a specific case where the answer was a system agnostic answer to question whose system was unclear here.
But we have no corresponding guidance for what to do when an answer which guesses the system gets placed on a question (usually moments before the question gets closed as being unclear).
I see such answers as an issue for a couple of reasons at least. For one, having an answer to a question can be a disincentive for OP to update the question to meet community guidelines. There has been at least one case where an answer has been accepted by OP without them bothering to update the question to include the system.
Another is that answering when the system is unknown can create confusion for the asker as well as future readers and a guess, no matter how sure a guess, is never guaranteed to be correct. I have seen a question that looked very much like a 5e question turn out to be a custom system where the DM was combining 5e, 4e and Pathfinder rules which means that any answer would have been useless that had guessed before. I've also seen questions where OP was confused about the system and using the wrong resources.
Thus, to me, guessing serves only to create confusion and disincentivize the proper use of our systems here.
For the last several instances that I've seen, the answer has gotten deleted either by a diamond mod or by the community. This is sometimes combined with heavy downvoting. I can't recall specific examples right now, but I know in the past some answers have simply been downvoted and left undeleted.
What is the consensus from the entire community about how these answers should be handled?