Forum Moderators: open
If you have valuable information to add to a locked thread, just drop a note to a forum moderator with your proposal.
Q: Why do threads get locked some times on popular threads?
A: The visible thread will not always show you the amount of moderation, post removal etc that has gone on in the background. Some threads just become magnets for "sideways" posts and are not worth the time and resources needed to keep them live and civil. If you have valuable information to add to a locked thread, just drop a note to a forum moderator with your proposal. (-tedster)
Other times, threads are asked and answered (like this one), and further replies most often lead off topic to something else entirely.