Read only works. It is a nasty thing to do IMO.
It can be gotten around.
See Word 2007 & Later Key Data File Locations.

They could, just as effectively, create a global template holding their fonts / styles and have normal update to those settings every time it reboots. If they don't have any user with macros, personal keyboard shortcuts, personal styles, they have some ineffective workers!

A Global StyleSheet in Microsoft Word?