Automatic Update / WordPress Update check not working

Background info:
On a hostgator, standard, dedicated server
Created a new account on my WHM, then used cpanel quick install to install wordpress (v4.2.2 at the time) on domain.

Everything works fine, except it never updated. We are now on 4.3.1, and it still hasn’t updated. When I got to the upgrade core, it says it is up to date. When I click “check again”, stay says up to date.

I get notifications for my plugins to update on same installation, but nothing about WordPress.

Screenshot of the update core.

I called hostgator, and after 30 minutes they said that WP doesn’t auto update for every release? I think he just couldn’t figure out why and gave up.

What’s the deal with this?