There's nothing wrong with replying to much older threads with current info, nor does it cause problems.
One must've, at least, done a Search to have come across them; which is a good thing, as many topics have been posted about multiple times in the past 20 years.
Even resurrecting an old thread, there could still be new details brought to light, which wasn't available at the time of the original post, which may be helpful. If so, then by all means, go ahead & post to it with that new information. We certainly don't discourage it.