Yes, but if you look at the context, you'll see that sysAppDir is not actually used to theme the Applications folders in system domain (effectively, just the one that would on OS X be called /System/Applications).
Instead of theming Applications, it is instead used only to obtain path to the expected single folder that is the parent in the system domain; effectively, it fetches path to equivalent of OS X's /System (and only as long as it's called "System").
I added a todo for myself to clean this up, and make it clear how big of a hack this is. There must be a better way to fetch the path to System folder.
In the meantime, from what I can tell the new code is correct, and themes previously-unthemed /System/Applications, as well as local-domain and user-domain Applications folders.