Means what it says. The menu entry in the main menu does not get abbreviated. I never wrote about the application bundle file name in the Finder at /Applications or it's localized name. Nothing like this! Nor did I write about the app name in the application switcher (cmd-tab).Abbreviating "GraphicConverter 12" to "GC" does not work.
I really only just referred to the menu item abbreviation. It does not work on my macOS version. That's it. A pure bug report.