configtest and graceful are "commands" used by other scripts such as httpd (apache) and nginx scripts which can take alternate signals to do other actions

but even in your example, condrestart, try-restart, those aren't supported by pure systemd scripts - however if you were using the init.d version you could do the easy-to-remember/type service mysqld condrestart

Fortunately with 7.0 you can keep using the old init.d scripts and custom commands, hopefully that will never go away with any of the later 7.x versions (I don't see why).