It's common on HN to include the year in the submission title if it's over a year old. As only the submitter or a mod can edit the title, commenters often prompt an edit as your parent did. It's not a comment on the worthiness of the submission: it's an aid to the readers.
Looks like the 'edit' link has disappeared for an unknown reason.
It disappears very quickly after you post. You only have a short time (minutes?) before your post belongs to the ages.