One common thing I've noticed from working in web publishing for the past couple of decades is that design is often created to serve the frequent homepage reader who is familiar with your publication, not the first-time entrant who came in via an individual page. The unstated assumption is that you will start on the homepage, and navigate from there to the article you want to read. Leaving the year off of the article isn't an anti-pattern to them because it should be clear that it's recent from the fact that you found it on their homepage.

Never mind that this rarely matches with reality. Even with pretty comprehensive web analytics to show actual usage patterns, it's common for site developers, designers, and publishers to make decisions based on this unconscious bias.