More often blogs and content sites are de-emphasizing the temporal nature of what they publish . In broad terms they are moving to be a collection of published articles, and publishing timely content on social networks.
Winer's original definition of weblogging was:
"A weblog is a hierarchy of text, images, media objects and data, arranged chronologically, that can be viewed in an HTML browser."
Primarily being "arranged chronologically" is becoming less important . Sites like Medium or corporate blogs like KISSMetrics or Intercom make the timestamp less obvious. It isn't in the URL, nor often prominent on the page. I believe this is happening for several reasons:
RSS is dying. People no longer re-visit sites frequently to check for what is new, nor have robots do that work for them. They are discovering content in different ways, primarily through social networks, and coming in the sidedoor of sites.
Social networks have won the war for short-form, timely content. Those micro-blogging platforms are largely time-ordered and that is what people choose to publish there.
Downplaying the timestamp attempts to make the content appear more evergreen. There is often an (unfortunate) positive association between being new and being relevant. For some publishing the timing is highly relevant, but many other subjects don't change in weeks or months. Calling out that it is, say, tenth months old might prompt readers to look for a newer answer elsewhere.
The takeaway is that there is an opportunity for platforms and authors to better structure their content. If most readers are arriving on individual posts, how can they be lead to other relevant material? Perhaps it better in categories, dynamic suggestions based on the content, or personalized recommendations based on the reader. The criteria should be about relevance and quality, not just freshness. There have long been plugins for "related posts" or "popular posts" that seem simplistic compared to how content could be organized or recommended.
As a thought exercise I have long wondered why media publications have not built such a system to tailor my reading experience. Instead they have largely continued to ape their printed roots in their digital products. As an example, I subscribe to the New Yorker in both magazine and iPad form. They present the list of current articles each issue. It would be better if they learned that I will read any Atul Gawande or George Packer article, and would want them to highlight one that I missed. While some of the magazine's coverage is time-sensitive (e.g. unfolding events in Syria) much of it is not. Despite my years of reading and expressing preferences they have learned little about me, similar to the New York Times or Boston Globe. I have a small hope that Jeff Bezos will bring some of the Amazon's personalization to the Washington Post. In the meantime some of the newer publishing platforms are experimenting with a different way to explore.