Not really. They even mention in the article that they did this twice last year. It's literally what they do year in and year out. It would almost be stranger if they didn't do it. However, this is all testing waters. Every year they do it to see how the international community responds. It lets them know how much power they have in negotiations.
Now what you just pointed out. The lack of any real response this time may very well encourage them to do more. But as of right now, it's business as usual. I mean unless you think shooting rockets this time instead of ballistics is an escalation.