Peak "Shadow IT"? Maybe it took too much effort to post it on the company blog.
(Maybe they maxed out their user account quota on Jira and couldn't post a ticket to get someone to publish their article. Not that anything this silly could happen in a multinational corporation. I'm surely imagining experiencing that.)
Maybe it's their new approach to marketing. To reach people on popular sites in "look, we're using this site too - we're cool and so modern and no different than you ordinary human" way
It does seem totally bizarre to me to make a big product announcement on a third party's website.