From what I understand, its not that moderators won't handle all reports for posts made more than 6 months ago, but only in cases mentioned in that message so for example if you want to report old post that has malware link, they will act on that so blocking it for all posts made more than six months ago woulnd't make sense.
That's the point I want to know what's the other reason to report an old post, because it's usually about to clean the forum. But yeah a malware link seems to be one of the reason why it should be reported regardless how old or new the post is.
Why do we've double standard for deletion, then? Is there any explanation for such?
Because if your post get deleted manually by the moderator, it's mean the problem is from your post. But if your post got deleted because the moderator deleted the main thread, it's mean your post high likely not broke the forum rules.