I always thought it was a little silly that they're so strict on that one rule. I would love to see more flexibility and common sense applied to locking "necro" threads.
Lore, as you said, doesn't date as fast. For example, discussions on the books and audiobooks are still relevant, unless they stop making them available. It just stymies conversation locking such threads.
I would also argue the same for troubleshooting threads - if something is still an issue with the game, it's still an issue. Forcing folk to create duplicate threads because something is over a month old, seems counter-productive and makes looking for solutions harder.
Obviously, if a discussion is based on out-dated information, it makes total sense to lock it. Most of the Feedback and Suggestions posts would get dated very quick.
If auto-locking could apply on a subforum by subforum basis, that would be the ideal.