Yea that's the legacy "classic" swarm from pre-2016. Docker isn't moving away from Swarm, in fact they keep adding features. See https://www.bretfisher.com/the-future-of-docker-swarm/

Last month they released https://github.com/docker/stacks for Swarm.

Also, every industry survey I've seen in the last year on orchestrator uses shows increases in overall usage of K8s and Swarm, which I consider the better measure of a project's health. (CNCF, Digital Ocean, F5, Sysdig)