In theory, the systemd developers could resurrect systemd-consoled as a tmux replacement. It already had a DEC VT style terminal emulator, knowledge of these systemd abstractions, and Desktop Bus capability.
But as pointed out already on this page, that would be to miss the wood for the trees. There are many programs that are hit by the fact that they call daemon() with the idea of escaping being killed at the end of the login session and yet are still (now, as of systemd version 230) killed by systemd at (final) logout. The systemd developers themselves mentioned screen and tmux. But others have already mentioned mosh-server and deluged (ironically in the bug report that supposedly drove this systemd change). It will almost certainly affect things like emacs --daemon as well. The list grows on and on.
But as pointed out already on this page, that would be to miss the wood for the trees. There are many programs that are hit by the fact that they call daemon() with the idea of escaping being killed at the end of the login session and yet are still (now, as of systemd version 230) killed by systemd at (final) logout. The systemd developers themselves mentioned screen and tmux. But others have already mentioned mosh-server and deluged (ironically in the bug report that supposedly drove this systemd change). It will almost certainly affect things like emacs --daemon as well. The list grows on and on.
* http://askubuntu.com/questions/338135/
* http://blog.refu.co/?p=1296#comment-61675
Should the systemd developers fork emacs so that they have a logind-aware version of emacs --daemon?