Not clear from your reply whether you added it (as a mod) or you are announcing to the gp that the year has since been added as at the time of your comment (i.e. by the poster or a mod).
I consider adding a year to a post to be more of a janitorial service than moderation, similarly how some users can flag comments. But of course you can call it whatever you'd like
but don't have any ability to adjust the title of a post as you can.
I can't find the specific dang comment out of the zillions but you can just email hn@ycombinator.com if you are lusting after the power to fix the years in titles.
