I would say that the only piece missing is the notification to the user that the article content has been updated.
Let's say that I read your blog everyday. I've seen this post previously, read it, and the content is value-added. Now I notice that the same post is again at the top of your blog - why? When I click into the article it seems similar to me, at first glance.
I would suggest putting a highlighted notification at the top of the post that informs the read the content has been updated for the latest trands|content|info|your word here
Now it makes perfect sense to update the publish date, informs the user that there is new content in the article, and it makes perfect sense for articles that are as old as your example.