As you are aware, Ubuntu 18.04 LTS (Bionic Beaver) is the first long-term support release of the Ubuntu Linux operating system to ship with the GNOME desktop environment by default. The first Ubuntu release to adopt the GNOME desktop instead of Unity was Ubuntu 17.10 (Artful Aardvark), which reached end of life on July 17, 2018.
While Ubuntu 17.10 was considered a testbed for Ubuntu’s new GNOME-based look and feel, Canonical did their best to resemble the Unity interface used until now with a dock placed on the left side of the screen and panel on top of it. However, the new dock does not yet support interactive icons like the Rubbish Bin/Trash one.