Like many things on KYM, there is no solution, because it's all purely a community-based problem. The only way to help is if the userbase gets better at using the website
Things can trend for whatever reason, be it reasonable or not, and there's always going to be at least one uninformed person wondering why said article is trending and will ask. Whether the question has merit is a different topic, but there are a few things to be said about it.
An article can trend purely because some troll decided to bring it back just to cause a stir, and the main solution to that is to review the article for any changes, and move on if there is none. (basically "Don't feed the troll")
Often, articles can have notable developments that can have it trend due to it being currently relevant, but said notability is subjective, and sometimes niche. Not every article with a development will hit the front page, but if there is enough attention rightfully given to it, of course it's going to trend, and naturally curious people are going to wonder why.
Basically, if something trends, look at the comments first for some context, and if there isn't any reason for it to trend, don't ask. You can't make people not be able to ask that question, so it's all up to them. It's just something annoying you have to deal with.