If the tour's example question about "nosebleed seats" had never existed and were posted as a new question today, I would expect English Language & Usage site participants to close it within a day.
First, where is the research? "I've never heard of this idiom before today" doesn't qualify under even the most minimal interpretation of this requirement.
Second, consider this entry for nosebleed in the general-reference Merriam-Webster's Eleventh Collegiate Dictionary (2003):
nosebleed adj (1978) extremely or excessively high {seats in the nosebleed section} {nosebleed stock prices}."
This definition explicitly ties adjectival use of nosebleed to extreme or excessive height. Armed with that information, the poster would logically have had to narrow the question to something like "Why is nosebleed as an adjective associated with extreme or excessive height?" I would then expect new-question reviewers/close voters to argue that the question wasn't about the English language but about human physiology.
So the tour's example of a good typical question to ask at EL&U would, under current EL&U standards, be rejected because (1) it shows no research; (2) it's general reference; and (3) what's left of the question after the research and general-reference problems are resolved isn't a question about the English language but about the connection between altitude and nosebleeds. No wonder the handful of new question askers who actually take the tour before posting a question are likely to have a completely erroneous idea of what the site's current standards are.
Of course, one might try to rehabilitate the question by homing in on the "origin" aspect of the question to say something like this:
Merriam-Webster's Eleventh Collegiate Dictionary gives a first occurrence date of 1978 for nosebleed as an adjective in the sense of "extremely or excessively high." Where and in what context did this usage arise?
That version of the question would at least arguably be on-topic at EL&U: it shows research; it asks a question that isn't answerable by consulting a general-reference work; and it asks a question of a type that tends not to be closed as off-topic at EL&U. However, if anyone other than the original poster were to edit the question in this way, a vocal contingent of question reviewers on this site would strenuously object to the editing as an outrageous usurpation of the poster's ownership of the question. It would therefore seem appropriate to include a warning in the tour that revising an off-topic question to bring it on-topic is primarily (and perhaps exclusively) the original poster's task.
To provide an accurate picture of what EL&U expects of new questions in order to consider them valid, we would need to supply an example that satisfies all of these conditions. Perhaps even more usefully, we might consider adding a commentary (like the one in this answer) beneath the tour's current example question to give prospective question askers an accurate idea of what's in store for them if they ask a question like the one given there.
