It seems to me that its become standard practice on marketing type blogs for corporate websites to remove the date from their posts. I think its because (from personal experience) the company will go though a burst of "blog productivity" create a load of content but then not touch it for years, they don't want that content to look out of date or their website to look stagnant.
Removing the date from their posts, or any other content, hides how old it is and therefore obscures how active they are at crating new content.
Most companies try to use their blogs to attract new customers, a new customer may visit their website once or twice and will never see the blog again, it's not important that they do. They don't want it to look stale.
As a counter example, an interesting thread from yesterday [0] was about how CloudFlare use their blog not as a marketing tool but for technical content and attracting employees. They very regulally use their blog, and so keep the date on it showing how fresh it is.