Does (High) Sierra set a higher bar for menu bar apps?
It has nothing to do with a (perceived) "higher standard" for menu bar icons, it has to do with the privilege level of the process you are attempting to run (or restart from sleep).

In this case, to access the process that controls the fans, you need to have root level privileges.  Until you grant those privileges to that process, it won't run and thusly won't show up in your menu.