sudo is not installed by default on many distros (e.g. if you give a root password on Debian install, then sudo is not installed, but if you don't, it is so you

sudo is not installed by default on many distros (e.g. if you give a root password on Debian install, then sudo is not installed, but if you don't, it is so you can admin the system), so unless systemd introduces something to break sudo, I don't think it'll go away (it just may get bumped down the list of important packages). su seems to come from https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/ https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/, which is all the truly core stuff, and I don't see su disappearing from there.