Could it be that the teams are simply focused on adding K8s support and getting the Docker EE out of Beta?
Public statement on their blog after the K8s announcement in EU:
"But it’s equally important for us to note that Swarm orchestration is not going away. Swarm forms an integral cluster management component of the Docker EE platform; in addition, Swarm will operate side-by-side with Kubernetes in a Docker EE cluster, allowing customers to select, based on their needs, the most suitable orchestration tool at application deployment time."