Let me preface all this by pointing out none of these questions have actually been closed. Questions get random close votes all the time, sometimes for seemingly no reason. It's honestly not something to get concerned over unless those questions are actually closed incorrectly. Although you're certainly always welcome to leave a comment explaining why you think a question should remain to help dissuade any further close votes. If it does get closed, though, it's something that can be easily reversed by the community or a mod.
Something else to keep in mind is that just because a question is closed doesn't mean the information is gone. The question and answers are still viewable by everyone, and so the information is still there. That information is really only "lost" when the question is deleted. All closed question are a candidate for eventual deletion, but the community tends to avoid deleting older questions which are off-topic under todays rules, but still contain helpful information. Honestly the only thing closing really does is prevent new answers, and act as a sign post to other users saying "These kind of questions aren't a good fit for the site."
The two linked questions are voted to be closed because it's technical support for modded Minecraft. First of all, since the questions have good answers, why would you close it?? The answers could help someone with a frustrating problem! Furthermore, the questions were asked before modded Minecraft technical support was banned. So at the time, these questions were allowed.
When we make changes to our allowed-questions rules, then those rules apply to all questions, new or old. Keeping those question open will lead newer users to believe that support for modded Minecraft is on-topic, and if they then proceed to ask their own support question for modded minecraft, it'll be all the more confusing and frustrating when it's closed. It can be frustrating for other users too, since those off-topic questions need to be closed and can potentially clog up the front page.
If those old questions were closed, then that makes it clear to any user coming across those older questions that support for modded minecraft is off-topic. This reduces the number of off-topic question asked, reducing the frustration for everyone, including any potential askers.
There were quite a few more close votes that didn't make sense to me, for example on this question. Voted to close as a duplicate. This "duplicate" question literally has an answer that says "While not a direct duplicate of this Arqade question" and someone votes to close it as a duplicate of THE VERY QUESTION THE ANSWER ADDRESSED AS A NON-DUPLICATE. Seriously?
I'm by no means a Minecraft expert, but these appear to be duplicates to me. I know the questions answer says "these aren't exact duplicates", but that doesn't mean they're right If you disagree, I'd encourage you to leave a comment on the question explaining why you don't think they're duplicates. Such a comment can help the community decide whether or not it's actually a duplicate, and may result in the question remaining open.
Third and last example of an incorrect close vote: on this question, as a duplicate.
These close votes are just plain wrong, so really good catch on this one. The "original" question was asked in June 2019, whereas the "duplicate" was asked in April 2019. With the rarest of exceptions, we don't close older questions as duplicates of newer ones. It's normally the reverse: new questions are closed as duplicates of older ones. There are exceptions to this, but they're rare, and an exception doesn't apply in this case just due to the sheer downvotes on that newer question (since question quality matters for these exceptions).
The closers may think an exception is warranted since the newer question seems to have a better answer, but that would make a candidate for a merge, not a reverse closure (a merge would result in all answers being combined into one questions).
I've gone ahead and added a comment to this question, explaining why it shouldn't be closed, and to either cast reverse votes or flag for a merge instead.