Q:

Should we be undeleting questions that weren't relevant at the time, but now are relevant again?

Minecraft. 
Love it or hate it, it drives a lot of traffic to our site. Sure, recently we've had some bother with modded tech support questions, but overall, most of our questions/answers are fairly high-quality, and this is reflected in the substantial upvotes, bounties, views and comments on a lot of our questions (and answers).
Minecraft has been moving steadily onward, and as bugs were fixed or functionality was added/removed, we too updated questions, modified answers, and closed and deleted those which were no longer relevant.
Since that time however, Mojang has added the ability to select and load old versions of Minecraft from the launcher. Is that enough incentive to undelete well-written, well-maintained questions and answers?
For example, we have this question (10k+ only): How short can a minecart booster be and still be effective?
Minecart 'boosters' were due to an errant bug in the physics of how minecarts interacted with one another, which was fixed in Minecraft Beta version 1.6. With the ability to select a version prior to this, such as Beta v1.2, this question and answer is relevant again.
Should we vote to undelete this, and questions like it? (If yes, should a disclaimer then be added to the answer that states when the bug was fixed)?

Screenshots of the aforementioned question for those under 10k rep:

Question
Answer Part 1
Answer Part 2
Answer Part 3

A:

we need to look at the bigger picture. Are there any other questions for other games that involve older versions? How did we handle those? In case we closed some and allowed others, did we do that based on legal availability of the subject?
My personal opinion: if the game version can be acquired reasonably in a legal way (either because the game isn't updated automatically and requires manual patching, or because you can get older versions from the original source), a question that is only valid in that version is perfectly allowed. A question about an older (launcher-compatible) minecraft version is okay. A question about how to do a no longer obtainable quest in World of Warcraft is not okay.
badp claims that we should base our moderation on popularity. I personally think that is one of the worst ways we can moderate. We should NOT base our moderation on whether a game or a specific version of a game is played often. That just leads to favoritism and arguments about what games or versions we should allow.
We should base our moderation on whether the question has merit. Whether a question has merit depends on whether the problem occurs with a legal version of the game and whether the problem does not have a trivial solution (one that is answered by the game itself in a very clear way around the same time as you encounter the issue). It should NOT depend on how many people are playing the game.

A:

Yes, these questions should be undeleted and reopened.
As others have noted, these questions should not have been closed and deleted, since we have never agreed upon a policy of removing questions that are no longer relevant, due to version differences or inability to play the game in question.

