* apt/dpkg will remain the base packaging software on desktop and server. They're well-tested and familiar.
* flatpak will become the primary format for installing desktop software outside of repo. This'll be nice for some large open-source projects that cause grief for distro packagers, and will also give companies a single target for major Linux desktops. Flatpak is too narrowly-targeted to replace snap in all cases snap was designed for.
* snap will become a mechanism for image-based application deployment, primarily IoT.
* docker/lxd/whatever will be used to target immutable deployments, primarily servers.
Also; in the case of CoreOS, the base image is still built using a package manager (portage). Not sure about that other guy.