I just went to revive an old thread in Adult non-fiction (last post was in the spring) and saw the new alert. Now I'm feeling self-conscious about reviving it so I probably won't. I agree with Relaxed, such a weird rule and one I've never seen before on an internet forum.
Don't feel selfconscious - please feel free to revive - as long as you're not posting e.g. "Buy this book| it will be fine