Ubuntu – Upgrade from 14.04 to 16.04

In my experience, the beta version of Ubuntu will either upgrade automatically to the release or ask you if you want to do so via the update manager, once the release comes out. But be warned: the updated version may be "eccentric" if you don't do a fresh install of the release version.

New LTS releases are only offered at the first “point release”: 14.04.1, 16.04.1, (probably) 18.04.1, etc. This is done because by then most of the bugs that only show up after a release goes public will be fixed, and people who prefer LTS releases usually prefer a stable system that works without giving them too much trouble.

You can (temporarily) select the option to inform you about all new releases instead of only new LTS releases if you want to be offered an update now. But remember that there might be some issues that affect you still...