My apologies, I assumed that since you've been a user for a while you were aware of the reason for such a comment and the practice of indicating the post year in the submission titles.

No hard feelings, I hope.

Adding a date for older articles and posts is a very common HN convention

https://news.ycombinator.com/item?id=46896376

ideally it should be in the submitted title, if not often someone will post it as above .. and later a mod might add it.

No biggie, as they say.