With Ubuntu GNOME 20160323.1 amd64 step #5 of this behavior changed:
(1) Boot Ubuntu GNOME Xenial live image, wait for the standard boot menu to appear, and select Try Ubuntu GNOME.
(2) You'll find that the screen displays TTY1 + requesting a user name.
(3) Do nothing and wait 2 to 3 minutes after which a GUI login screen appears.
(4) Click on Live session user and a new screen appears requesting a password.
(5) Enter nothing and press Enter and you'll finally get to the live desktop.
A password is now demanded, just leaving it blank and pressing enter does nothing.
With Ubuntu GNOME 20160323.1 amd64 step #5 of this behavior changed:
(1) Boot Ubuntu GNOME Xenial live image, wait for the standard boot menu to appear, and select Try Ubuntu GNOME.
(2) You'll find that the screen displays TTY1 + requesting a user name.
(3) Do nothing and wait 2 to 3 minutes after which a GUI login screen appears.
(4) Click on Live session user and a new screen appears requesting a password.
(5) Enter nothing and press Enter and you'll finally get to the live desktop.
A password is now demanded, just leaving it blank and pressing enter does nothing.