I think the title needs to be fixed, it's a tad sensationalist. The Google Groups message is just "Container Linux project update" and is dated May 18th. Since then, there has been more clarification [0], [1], [2], that really calls out a rationalization of the RH roadmap and where CoreOS fits. It might be fair to say that RH doesnt plan to support "CoreOS Container Linux" in exactly the fashion prior to acquisition, but it would be disingenuous to imply it is being wholly discontinued.