I've done it many times. I think it adds to the discussion often times with information from posters no longer active. It also sometimes shows how knowledge on a subject has evolved. For example I revived a thread once on fish feeding where the discussion was about feeding dog food because it was cheap. It showed how far the state of the art had advanced for non-commercial pond fish feeding.
Another way you can bring old threads into a current discussion is provide a link to the old discussion within your post. This provides the information without actively starting the thread up. I do this frequently on topics I find of interest. Like this:
Band erosion and rock lining I keep a list of threads I am permanently interested in in my "watch list". Then I can access them again easily or add a link to a discussion where I think the information can benefit the current thread.
