I've removed identifying information because this is not about shaming people who share a common heuristic about valuing professional output, it is about adapting to that:
The social purpose of mentioning the age is *to apologize to one's own audience* that you are telling them Old News. These users are explicitly not not trusting the article, they model people dear to them as not trusting the article solely based on the age.
These folks often state that they are *surprised* that something as old as ten years old (with exclamation points!) could still be relevant.
How many more thousands of people said it! How many more tens of thousands merely thought it, and either read the advice but didn't share, read the advice but didn't apply to their lives, or stopped reading at date!