Old ways of installing Nautilus do not work.
install Desktop Folder from App Center
Strangely, VirtualBox was able to put an icon on the desktop. The .desktop file it created is in ~/Desktop/, no surpises there. And it works! So it looks as if the capability is still there, all they took out was the tools to create desktop items from the GUI. If you are comfortable creating .desktop files from scratch, it should be possible.