The applications menu is not updating to reflect newly installed applications in KDE, and I'm wondering if there's any way to force it.
Have you tried restarting the VM? This version of Workstation is pretty much out of support so it's going to be hard to figure out what exactly the issue is.
Is KDE version you're running Plasma 5? I remember reading an article which stated that this version of KDE dropped support for Unity mode as the current release of Workstation (14) no longer provides Unity mode for Linux guests.
I don't know how they are generated; but looking at VMware Workstation Pro 12.5.x on Windows, under each VM there is a folder named "caches" with subfolders named "GuestAppsCache" and "LinkIcons" and "Screenshots"
Under the GuestAppsCache there is a subfolder launchMenu and a file name launchMenu.menudata. It looks that the menu items are in this file. The format is not documented. So hand-editing would not be easy.
If you are willing to try it out, perhaps try moving out the GuestAppsCache and LinkIcons folders and see whether that forces Workstation 11.x to regenerate/rebuild the menu for a particular VM that you switch to Unity view mode.
Yeah, deleting the "caches" folder was the first thing I tried, but all that did was make all of the existing application icons reset into generic "new document" icons for a day or so - there were no other noticeable changes to the menu.