Necroing is Perfectly Fine
Stack Exchange, in general, and Worldbuilding in particular are not time limited Q&A forums. Any query asked now is considered valid and fair game forever, for the purposes of our present consideration. (People within this artform have considered the the concepts of a geopoet's individual mortality and the intellectual property we leave behind, but I don't think that's what we're getting at here!)
There are several reasons why it's not only okay, but also encouraged:
- There is a Badge. YAY! BADGES! In this case, the Necromancer Badge.
- Information Changes. A question might be asked, answered and green check accepted and well upvoted but that doesn't mean the context of the question remains static for all time. Circumstances change, new knowledge is gained. For example, Chasly asked a wonderful Lego related question back in 2015 about how Lego people reproduce. A number of wonderful answers were generated at the time. However, as years passed, the old answers expired or became less reasonable given new information. As of a year ago, this new information allowed me to necro the question and give a new answer to the question that would have been inconceivable before.
- New possibilities come to light. Touching on your statement that querents (and possibly respondents, by extension) are likely to forget they even wrote a question or answer, I think such a generalisation could be seen as just a bit of an insult to the human long term memory! Just this morning, I got a notification of an upvote for an answer I'd made several years ago on another stack forum. While happy enough for the upvote, it gave me cause to reread my response and improve it. I added links and a third possibility to the basic answer.
Long answer short: Necroing is Good.
Information Box Needs Work
In light of L. Dutch's comment to you:
Maybe I am misunderstanding your problem, but I see an "asked 6 hours ago" right at the bottom of your question.
I think he is misunderstanding! Or at least forgetting something!
I actually concur with you: it would be nice if that info box could be arranged so that all pertinent query data could be kept there. A quick perusal of queries in Main shows that the info box does sometimes tell us when the question was asked (so far so good!). But other times, the info box only tells us when the question was modified, or answered. And those instances, while recent, could in fact be months or years after the query was first asked. Queries in Meta behave differently: the info box always reports when the question was asked, never when it was edited or answered.
I can see how one could misinterpret that information.
I am positive that at the forum level Moderators have no control over the information displayed in the info box; but I do agree it would be a nice and useful feature were it added! Info boxes should probably also be made to behave consistently between Main and Meta as well. That would avoid a lot of confusion as well.