Today, the Fedora Project announced [1] a new project, Fedora CoreOS, which will serve as a successor to Container Linux and Fedora Atomic.
[1] https://fedoramagazine.org/announcing-fedora-coreos/
There's an FAQ [2] that addresses, among other things, the future of CentOS Atomic Host:
"CentOS Atomic Host will continue producing downstream rebuilds of RHEL Atomic Host and will align with the end-of-life. The Fedora CoreOS project will be the consolidation point for the community distributions. Users are encouraged to move there in the future."
[2] https://coreos.fedoraproject.org/faq
Red Hat has announced [3] plans to ship a product called "Red Hat CoreOS." It's my impression that the delta between the Fedora CoreOS project and the Red Hat CoreOS product will be small enough that there won't be a need for a CentOS CoreOS.
[3] https://www.redhat.com/en/about/press-releases/red-hat-unveils-roadmap-coreo...
There are limited technical details about Fedora CoreOS available at this point, but the new host will be based on the same rpm-ostree foundation on which Fedora Atomic and CentOS Atomic are now built.
I encourage CentOS Atomic users interested in the future of the platform to get involved [4] in the new project, and come say hello in #fedora-coreos on freenode.