I came across a question today that I had been pondering for a while, and after reading and thinking about the answers I noticed it had been asked and answered 3-4 years ago. UX, especially on the web, is evolving at such a rate that having something even 2 years old could be completely out of date. I was considering asking the question again to spark a more modern discussion, but that would technically be a duplicate question.
I feel like UX is time sensitive enough that a button to request for a more up-to-date answer is needed. This would take the old question and throw it back into the newly asked questions, perhaps putting the old answers into a separate section labeled by the initially asked question date. The person that re-asked the question would then take over as the author and pick a new answer as would normally happen.
I feel like this cleanly solves an issue that needs to be addressed soon as some major questions get outdated.