[rcxdude]

It makes the presence of those libraries optional: you no longer need them to execute the relevant tool at all. It'll just mean you can't use features which depend on those libraries. For libraries that are only pulled in for less-commonly used features it makes a lot of sense (the specific case they are doing it for is generating the initrd, which needs a copy of any libraries used by anything running in the initrd, which is almost always going to include systemd, but the systemd in the initrd is very unlikely to use any of these optional features)